A group of military officers in Guinea-Bissau has claimed “total control” of the country, a day after two leading candidates in a tightly contested presidential election each declared victory.

Calling themselves the “High Military Command for the Restoration of Order”, the officers read out a statement on television on Wednesday, declaring that they had ordered the immediate suspension of the electoral process “until further notice”.

They also ordered the closure of all land, air and sea borders and an overnight curfew.

The move came shortly after sustained gunfire was heard near the election commission’s headquarters, the presidential palace and the Ministry of the Interior in the capital, Bissau.

The results of Sunday’s presidential vote – which pitted President Umaro Sissoco Embalo against his primary challenger, Fernando Dias – had been expected to be announced on Thursday in the West African nation.

“I have been deposed,” Embalo told French broadcaster France24 in a phone call, adding that he was “currently at the general staff headquarters”.

Reporting from neighbouring Senegal on Wednesday afternoon, Al Jazeera’s Nicolas Haque reported that Embalo was under arrest.

The head of the main opposition PAIGC party, Domingos Simoes Pereira, has also been arrested, Haque said. “As well, we’ve just heard that the military is trying to cut off the Internet. There’s a curfew in place.”

He added that the army officer leading the coup, Denis N’Canha, served as the head of the presidential guard. “The man supposed to protect the president himself has put the president under arrest,” Haque said.

Disputed presidential vote

Guinea-Bissau has experienced several coups and attempted coups since it gained independence from Portugal in 1974.

The legitimacy of this week’s election was called into question by civil society groups and other observers after the PAIGC was barred from running in the presidential race, Haque reported.

“There was going to be a stalemate over who was going to win this [week’s] election, and that is when the military stepped in,” he said.

Both Embalo and Dias had already declared victory with little proof to support their claims.

“There won’t be a second round,” Embalo’s campaign spokesperson Oscar Barbosa told the AFP news agency on Tuesday, adding that the president “will have a second mandate”.

Dias also declared victory, saying in a video posted to social media: “This election has been won. It has been won in the first round.”

Guinea-Bissau’s last presidential vote in 2019 was marked by a four-month post-election crisis as both main candidates claimed victory. That election had pitted Embalo against Pereira.

Calls to restore constitutional order

Meanwhile, West Africa’s ECOWAS and African Union observers expressed concern over the military takeover in Guinea-Bissau, according to a joint statement issued by the organisations.

“It’s regrettable that this [coup] announcement came at a time when the missions had just concluded meeting with the two leading presidential candidates, who assured us of their willingness to accept the will of the people,” the observers said.

The observer missions that included Mozambique’s former President Filipe Jacinto Nyusi and Nigeria’s former President Goodluck Jonathan, called on the regional bodies to take the necessary steps to restore constitutional order.

“We urge the armed forces to immediately release the detained officials to allow the country’s electoral process to proceed to its conclusion,” the statement from the Economic Community of West African States and African Union observers said.

United Nations Secretary-General Antonio Guterres has also been following the situation in Guinea-Bissau “with deep concern”, spokesperson Stephane Dujarric said during a news conference in New York, adding that the UN chief appealed “to all national stakeholders in Guinea Bissau to exercise restraint and exercise and respect the rule of law”.

“The secretary-general will continue to closely follow the situation in the country as it unfolds,” he added.

The Portuguese government also called for all parties to refrain from “any act of institutional or civic violence”. In a statement, it said Guinea-Bissau’s state institutions must be allowed to function in order to finalise the electoral process.