The impact of the increasing fighting in Yemen is now visible beyond its borders.
According to Saudi officials, Houthi rebels have attacked the country's two major airports, Riyadh and Abha, with missiles and drones within two days.
Three people died and dozens were injured in these attacks.
These attacks have taken place at a time when the Houthis have given a 'final warning' to international airlines against using Saudi Arabia's airspace.
Houthi army spokesman Yahya Sarri has claimed that Saudi Arabia's airspace has now become "the center of their military operations".
Houthis called it a retaliation
The Houthis also claimed to have launched another missile attack on Riyadh's King Khalid International Airport on the night of Wednesday and Thursday.
Saudi Arabia's civilian airports have been targeted before as the fighting in Yemen intensified.
The Houthis say that these attacks have been carried out in response to Saudi Arabia's military actions in Yemen.
At the same time, Saudi Arabia has said that it will take further action in response to these attacks.
These attacks have taken place at a time when fighting is intensifying on different fronts in Yemen. Both sides appear to be entering a new phase of this conflict.
Saudi Arabia's civil aviation department 'General Authority of Civil Aviation' or GACA issued a statement on Wednesday.
It said that two people were killed and 28 people were injured in the attack on Abha International Airport.
In a separate attack, one person was killed and eight were injured at King Khalid International Airport in Riyadh, the capital of Saudi Arabia.
According to Gaqa, the two women killed at Abha airport near the border with Yemen were citizens of Morocco and Algeria.
At the same time, the person killed at King Khalid Airport was a citizen of Sudan and was living in Saudi Arabia.
Saudi Arabia's Civil Aviation Department did not say who was responsible for these attacks.
However, Houthi army spokesman Yahya Sari said that their fighters had attacked both Saudi Arabian airports with ballistic missiles and drones.
The military spokesman of the Houthis also said that the Houthis had attacked Yemen's Aden International Airport on Wednesday.
This airport of Aden is an important international route to those areas of Yemen which are not under the control of Houthis.
Whenever fighting intensifies in Yemen, this airport is repeatedly targeted.
Yahya Sari said the attacks on both Saudi Arabian airports were "in response to Saudi attacks against our country."
He claimed that Saudi Arabia had launched "60 air and missile strikes in the last 24 hours".
Why are the Houthis targeting airports?
Danny i.e. Denis Citrinovich is a senior researcher at the Institute for National Security Studies (INSS), monitoring the affairs of the Middle East, Iran and Yemen.
According to him, the Houthis' targeting of airports is not just a military action.
This is also part of their political strategy and attempt to create mental pressure on people.
While talking to BBC Urdu, Danny mentioned an earlier statement given by the Houthis.
In this statement, the Houthis had said, "If our planes cannot land at Sana'a Airport, then the planes of any civil airline should also not land in Saudi Arabia."
According to Danny, this is the main reason for the Houthis to attack airports.
He says that the Houthis want to send a message to Saudi Arabia, "If Yemen is under siege, then Saudi Arabia should not consider itself safe from the effects of this war."
"This means that if the restrictions on Sana'a airport continue, Saudi Arabia's civilian airports will also not be able to function normally."
According to Danny, these attacks on airports are part of this thinking of 'siege in response to siege'.
He says, "The Houthis are attacking airports for this very reason. At present, there are no signs of these attacks stopping. This is the first and biggest reason for this."
Danny says that the purpose of these attacks is not only to disrupt air traffic.
Through these attacks, Houthis want to affect the morale and mental state of the people of Saudi Arabia.
According to him, Houthis sometimes target airports which are used for civilian flights as well as military purposes.
He says that by attacking such airports, the Houthis want to affect or increase pressure on Saudi Arabia's ability to take military action.
However, according to him, the main idea behind it is still 'siege in response to siege'.
'Attempt to influence Saudi Arabia's air traffic'
Ahmed Naji, senior analyst on Yemen affairs at the International Crisis Group, also believes almost the same.
According to him, the Houthis are gradually increasing tension to increase pressure on Saudi Arabia.
Initially, the Houthis blockaded sea routes to harm the interests of Saudi Arabia.
Now they are disrupting Saudi Arabia's air traffic by targeting airports.
Ahmed Naji told BBC Urdu that airports are such a target for the Houthis, where attacking or threatening to attack does not affect only the officers.
This affects ordinary Saudi citizens and travelers from other countries.
"This could disrupt flights, create uncertainty and attract media attention," he says.
According to Ahmed, threatening an attack or disrupting normal operations at an airport "makes headlines instantly and can impact people's daily lives."
He says that the Houthis have their eyes on this very thing.
The Houthis feel that "increasing pressure on Saudi Arabia may eventually force Riyadh to reconsider its assistance to Yemeni government forces fighting against the Houthis."
Are airport attacks a sign of rising tensions?
Are these attacks a sign of further intensification of this conflict?
What do these attacks reveal about the Houthis' capabilities and intentions in the future?
In response to these questions, Denis Citrinovich says that the situation is definitely becoming serious.
He says that these attacks are not new in terms of the places where the attacks are being carried out.
Houthis have been targeting Saudi Arabia's airports and other important places in the past also.
However, now attacks are happening more frequently than before and are being carried out continuously.
He says, "The Houthis are now carrying out continuous attacks day and night."
According to him, such continuous attacks are a clear sign of increasing tension.
For this, he gives the example of attacks on oil bases, airports and ports like Yanbu of Saudi Arabian oil company Aramco.
He says that behind this also the thinking of 'siege in response to siege' is working.
Along with this, one of the objectives of the Houthis is to impact the oil exports of Saudi Arabia.
Dennis believes that these attacks are a clear sign of this conflict becoming more intense.
According to him, the attacks of Houthis are unlikely to stop. Especially at a time when Saudi Arabia is also increasing its military actions.
He says it is difficult to formulate an effective strategy against the Houthis because "whenever pressure is increased on them, they respond more quickly than before."
Danny believes that the difficulty for Saudi Arabia is that the Houthis will not stop until their main demands are met.
These demands include ending the sanctions imposed on Yemen and its siege.
He says, "If there is no major change on the battlefield, these attacks are likely to continue. Especially at a time when both sides are increasing their military actions."
He also believes that "another challenge before Saudi Arabia is that despite having a security system to protect against air attacks, it is not able to stop all the missiles and drones."
He says, "Recent attacks have made it clear that the Houthis still have the ability to target important places."
Ahmed Naji also believes that the capabilities of the Houthis have increased significantly in recent years.
However, he doubts how long the Houthis can maintain this capability.
He told BBC Urdu that the Houthis have been successful in acquiring modern drones, missiles and other military equipment.
However, according to Ahmed, the Houthis' ability to maintain this level of tension for a long time is not "unlimited".
He says, "Continued attacks against Saudi Arabia could ultimately reduce their stockpile of military equipment."
Ahmed Naji gives the example of Houthi attacks against Israel for this.
He says, "At one time the Houthis increased the number of their attacks against Israel. But over time the pace of these attacks decreased as their ability to continue such attacks decreased."
"A similar situation may be seen in attacks against Saudi Arabia."
Ahmed believes that "the Houthis are playing a gamble."
According to him, the Houthis probably feel that "continued pressure will ultimately force Saudi Arabia to reduce aid to the government of Yemen."
"But if Riyadh does not back down, this conflict could turn into a protracted and exhausting war for the Houthis."
Ahmed told BBC Urdu that if the fighting continues for a long time, the Houthis will have to use a large number of missiles and drones.
According to him, "This may weaken their military position over time."
According to Ahmed Naji, the attacks of the Houthis show that they are capable of taking military action against Saudi Arabia.
But these attacks also raise the question whether the Houthis can continue such intense fighting for a long time?
Why is the fighting intensifying in Yemen?
The ongoing civil war in Yemen has intensified in the last few weeks.
Houthis control most of the areas in the north-western part of the country.
Recently, the Houthis advanced rapidly and captured many important areas on the Red Sea coast.
These include the Mokha port built on the Bab al-Mandab strait.
Bab al-Mandab is the narrowest part of the Red Sea. It is an important route for ships from all over the world.
However, Yemeni government forces, backed by Saudi Arabia, later said they had "secured" the Bab al-Mandab strait at the southern end of the Red Sea.
These forces also announced to wage a full-scale war to take back all the areas occupied by the Houthis.
The US Embassy has said that American citizens should exercise more caution than usual in view of the recent attacks and threats made by the Houthis against Saudi Arabia's airports and its airspace.
The embassy has warned that passengers may face problems like cancellation of flights, temporary closure of airspace and disruption in travel plans.
American citizens have also been advised to avoid going near the Yemen border.
The impact of the attacks was also visible on air traffic.
Flight tracking website Flightradar24 said in a post on Thursday that Riyadh's airport was back in operation.
However, at that time it was at the top among the airports in the world where flights were facing the most disruptions.
The website had earlier said in another post that flights to Riyadh were once again circling in the air waiting for permission to land.
At that time the last plane had landed about 30 minutes earlier.
decade long struggle
The Saudi Arabia-led coalition was formed in 2015.
At that time, Arab countries had jointly launched military action to prevent the Houthis from removing Yemen's internationally recognized government from power.
There was a ceasefire for some time in the year 2022.
Before this, millions of people were affected by air strikes and ground fighting that went on for several years.
Millions of people died and one of the world's most serious humanitarian crises arose.
UN Secretary-General Antonio Guterres has condemned the Houthis' "continued cross-border attacks" on Saudi Arabia.
He said he was "extremely concerned about the rapid escalation of fighting".
There are reports of hundreds of people being killed on both sides following the recent advance by the Houthis.
The United Nations said on Wednesday that due to the worsening situation, more than two lakh people had to leave their homes.
