The president who was ousted in the coup, Umaro Sissoco Embalo, arrived in Senegal on board a special flight following an intervention by the West African regional bloc, Senegal's foreign ministry said in a statement..
It was the ninth coup in West and Central Africa in five years and continued a pattern of instability in Guinea-Bissau, a notorious cocaine transport hub with a long history of military interventions in politics.
The self-styled "High Military Command for the Restoration of Order" announced in a televised statement on Wednesday, local time, that they had seized power from Embalo.
They said the move came in response to a destabilisation plan involving politicians and drug barons, without going into more detail.
Wearing a military uniform and flanked by other military officials, Inta-a made his first public appearance as leader at a ceremony broadcast on Thursday on state television.
He said the coup was necessary to stave off a plot by "narcotraffickers" to "capture Guinean democracy" and said the transition would last one year, beginning immediately.
At a swearing-in ceremony later on Thursday, he named Major-General Tomas Djassi as army chief of staff.
The takeover came a day before provisional results were due to be announced in the race between Embalo and Fernando Dias, a 47-year-old political newcomer who had emerged as Embalo's top challenger in the presidential vote.
Before the coup announcement, gunfire rang out in the capital Bissau for about an hour on Wednesday near the electoral commission headquarters and presidential palace.
Embalo called French media to say he had been deposed.
An army statement dated on Thursday and published before Senegal announced Embalo's evacuation said Embalo and other top officials were "under the control of the High Military Command".
African Union chairperson Mahmoud Ali Youssouf condemned the coup in a statement and called for the release of Embalo "and all detained officials".
Heads of state from the West African regional bloc ECOWAS also condemned the coup and later held a virtual meeting to discuss the situation, according to a post on social media platform X.
Screen grabs shared with the post showed several regional leaders participating, including the presidents of Nigeria, Senegal, Sierra Leone and Liberia, as well as the AU's Youssouf.
The European Union said constitutional order should be restored and the vote count allowed to proceed.
Central Bissau was mostly quiet on Thursday, with soldiers on the streets and many residents staying indoors, even after the overnight curfew lifted. Businesses and banks were closed.
"I'm very concerned about the prevailing situation," Julio Goncalves, a 30-year-old professor and Bissau resident, said.
"No pharmacy is open. If somebody is sick how can he buy medicine or go to the hospital?"
Before Inta-a's presidency was announced, Dias accused Embalo in a video statement of staging a "false coup attempt" to derail the election because he feared he would lose.
In a statement to Reuters on Thursday, the coalition backing Dias demanded that authorities be allowed to release results from Sunday's presidential election.
The coalition also called for the release of former prime minister Domingos Simoes Pereira, who was detained on Wednesday, according to relatives and security sources.
