Zambia's President Hakainde Hichilema has been re-elected for a second five-year term after securing a 60% share of the vote, the electoral commission has announced.
Hichilema's win was widely expected, with his closest challenger Brian Mundubile getting 38% of the votes cast. The remaining 12 candidates trailed far behind.
The result came after a contested process, with 55-year-old Mundubile earlier claiming victory and alleging, without providing evidence, that there had been voting irregularities.
His party, the NRPUP, told the BBC that Mundubile was in a "secure location under the protection of an international human rights body due to threats made against him".
"He will communicate directly with the Zambian people and the media as soon as circumstances allow," the party said on Tuesday.
Local media reported that Mundubile and his running mate Makebi Zulu had gone into self-imposed exile at a UN agency in the capital, Lusaka, fearing arrests.
It came after some leading opposition figures were arrested in a raid on Friday who the authorities accused of plotting an insurrection. Mundubile called the claim a fabrication.
In a statement after being declared the winner, Hichilema, 64, said: "We are truly humbled by the trust you have placed in our hands."
He said the election showed that Zambia was a place of peace, law and order and a "democratic nation that settles our differences at the ballot box, and nowhere else".
"To those citizens who preferred the ideas presented by our opponents, we hear you, and we will continue to work for you," he added.
Hundreds of Hichilema's supporters, dressed in the red colours of his United Party for National Development (UPND) flooded the streets of the capital to celebrate after the results declaration.
Zambia has a record of peaceful transfers of power. Since the return to multiparty democracy in 1991, presidential transitions have occurred through the ballot box.
It is unclear if the opposition will challenge the election result.
Mundubile had earlier alleged there had been discrepancies between polling-station results and those officially announced and claimed military involvement at tallying centres.
On Monday, Mundubile described Friday's raid by armed personnel at his home in Lusaka saying they had knocked down the gate with an armoured vehicle, broke doors and windows and opened fire.
He denied allegations that high-grade military weapons were being stored at his home as well as the presence of any militia as the authorities had alleged.
"So they came in to kill us," he told the BBC on Monday.
Mulambo Haimbe, Hichilema's election agent and a senior UPND member said Mundubile's remarks regarding the incident were "not correct".
He told the BBC's Newsday programme on Tuesday that criminal charges were being put forward against those arrested.
He also said the courts would address the various matters should the opposition party challenge the election outcome.
A day after polling, the electoral commission briefly suspended counting and the announcement of results, citing reports of violence targeting polling staff and the theft of marked ballot papers in some areas.
The suspension was lifted the same day.
Regional and international observers described the election day as largely peaceful and urged all sides to remain calm and respect the official process.
They did however raise concerns about late electoral reforms, media freedom and access to the media in the run-up to the poll.
Samuel Tembenu, a former minister from Malawi, who was leading the observer mission from the southern African bloc (Sadc), is quoted by the AFP news agency as saying that his team had "recorded, but could not verify, reports of intimidation, assault, abduction and damage to property in five provinces".
Observers also expressed concern over the brief suspension of the vote counting, saying it risked the credibility of the process as well as voter confidence.
The EU observation mission warned at the weekend that restrictions on the opposition in the campaigning period may have contributed to an "uneven contest".
