The army in the west African state of Guinea Bissau says it has seized power and dismissed the government.
Soldiers announced they were setting up a transitional government to include "all national political orientations" to be headed by the armed forces chief of staff General Verissimo Correia Seabre.
All government ministers have been ordered to report to a public building in the capital of the former Portuguese colony.
Radio stations have broadcast a message from the army saying it had seized power because President Kumba Yala had failed to resolve the country's problems.
President Yala dissolved the government last November, promising new elections but they have been postponed four times since.
On Saturday, the body in charge of elections said the president would have to cancel them again.
According to the BBC's West Africa correspondent Paul Welsh the coup appears to have been peaceful.
Yala (right) has reportedly been arrested
In a radio broadcast Lieutenant Colonel Jose Zamora Induta read a statement saying "there was no shooting, nor will there be any shooting," the Portuguese news agency Lusa reported.
Portugal condemned the coup and called on the army to allow
long-delayed elections to go forward in its former colony.
"The Portuguese Government deplores the military coup d'etat
that occurred today in Guinea-Bissau and calls on its perpetrators
to immediately re-establish constitutional legality... ," the foreign ministry said in a statement.
Lusa said the head of the armed forces had urged civilians to "avoid acts of vandalism".
The agency said a curfew has been imposed from 0700 to 1900.
It said troops were seeking to detain the Prime Minister, Mario Pires, who is in the south of the country.
Guinea-Bissau is one of the poorest countries in the world and has been beset by food shortages and strikes.
It has never really recovered from an army revolt and then a war in the late 1990s, our correspondent says.
The secretary-general of the United Nations said in June that the country was embarking on a downward course.
The Organisation of West African States recently said it was worried, not least by the silencing of political opponents of the president.