Four dead and thousands stranded as heavy rain triggers unprecedented floods in eastern Japan

At least four people have died in eastern Japan as heavy rain flooded roads, cut power and left thousands of travelers stranded overnight at Tokyo's Narita airport, authorities said Friday.

More than 36 centimeters (14 inches) of rain fell in 24 hours in parts of Chiba prefecture, which borders Tokyo, triggering landslide warnings and power outages for nearly 25,000 households.

The downpour struck during one of Japan's busiest holiday weeks, prompting the Japan Meteorological Agency (JMA) to issue its highest-level heavy rain warning for the region for the first time.

A JMA official on Thursday said this was "shaping up to be an unprecedented level of heavy rain."

"This case was an extremely unusual situation, even by Japan's historical weather standards," Chiba Governor Toshihito Kumagai told reporters early Friday. "I have responded to many disasters in the past, but I have never experienced a case like this."

The Chiba Prefecture Disaster Management Office said those confirmed deaths included a man in his 60s or 70s found on a flooded road and a 66-year-old woman found in her submerged car.

A third victim was a man of unknown age found collapsed in the street, and a fourth was a person whose age and gender have not been determined, AFP reported. A fifth person is feared dead and a sixth remains unaccounted for. Soldiers have been deployed to help with relief efforts.

More than 6,000 people were stranded overnight at Narita, one of Tokyo's two major international airports. Many train services to and from the airport were also canceled into Friday afternoon.

"I never thought I'd spend the night at the airport but it is what it is and we are learning," a traveler told Japanese public broadcaster NHK. "We're never going to forget this trip."

Hundreds more were stranded at Chiba station after train services were suspended. Several people spent the night in shelters. NHK footage also showed cars submerged up to their headlights in Kashiwa city.

Major highways in Chiba, including routes connecting Narita to central Tokyo, remained closed Friday, according to highway operator NEXCO East, forcing drivers onto alternate routes. Some train services connecting Narita to Tokyo had resumed early Friday.

An airport spokesperson said all flights were scheduled to operate normally, and Japan Airlines said some delays were possible, but no cancellations were expected.

The level-5 heavy rain warnings issued Thursday were downgraded to level 4 by Friday morning.

Scientists warn that human-driven climate change is making extreme weather events more frequent and intense.