Soldiers have taken control of the capital of Guinea-Bissau and are holding both the prime minister and interim president.
Prime Minister Carlos Gomes Junior was seized in an assault on his homelate on Thursday. Interim president Raimundo Pereira is also being held.
A military group has issued a statement saying it is not interested in power, but acted because of a secret deal with Angola, which has 200 troops there to help reform the military.
The UN Security Council has condemned the coup in the former Portuguese colony and urged the immediate restoration of civilian authority.