Leaders of Guinea-Bissau's military coup set out their terms for a ‘unity government’ Friday, a day after seizing control of the capital and capturing both the prime minister and interim president.

In a statement released late on Friday they said that army chief-of-staff General Antonio Indjai had also been deposed.

Army chiefs had earlier met leaders of the political parties, telling them to consider what they called ‘a government of national unity’ in which the coup leaders would control the defence and interior ministries.

"The soldiers told us ... to think about a government of national unity and its composition," one party leader, who requested anonymity, said.

"In this government the posts of ministers of defence and interior would go directly to them," the politician added.

Those terms were confirmed by another person who attended the meeting, which was held behind closed doors at the former military headquarters in the southern suburbs of Bissau and which lasted for more than a hour.

General Indjai was among those who attended that meeting, they said.

Also present were the deputy chief-of-staff, General Mamadu Ture Kuruma; the heads of the army, air force and navy; the army's spokesman and four colonels.

All the main political parties were represented at the meeting, but there was nobody from what was until Thursday night the ruling African Party for the Independence of Guinea-Bissau and Cape Verde (PAIGC).

Deposed prime minister Carlos Gomes Junior, the favourite in a second-round presidential election set for this month, was seized in a military assault on his home using rocket-propelled grenades Thursday previous evening.

The military also captured interim president Raimundo Pereira.

"The army confirms it has deposed the interim president Raimundo Pereira, the prime minister Carlos Gomes Junior and the army chief-of-staff General Antonio Indjai," said Friday's statement from the ruling "military command".

"The three are safe and sound and are under the control of the army," it added.

Gomes had garnered 49 percent of the vote in the first round of the election on March 18 and campaigning for the second round was supposed to start Friday.

But on Thursday evening, soldiers armed with rocket-propelled grenades and Kalashnikov rifles launched their power grab. Gunfire and ambulance sirens echoed through a city plunged into darkness as electricity was cut off.

A military source said the arrested prime minister had been taken to army headquarters at San Vincente, 45 kilometres (28 miles) north of the capital,

but the whereabouts of the president were not known.

Troops also seized the ruling party headquarters and the state radio station. On Friday, heavily armed soldiers were patrolling the streets of Bissau. They were also gathered at the finance and justice ministries.

The international community denounced the coup.

The UN Security Council "condemned the military action and urged the immediate restoration of civilian authority", US ambassador to the United Nations Susan Rice said after council talks on Friday.

The US embassy in Senegal said: "It is regrettable that elements of the Bissau-Guinean military have chosen to derail the democratic process."

The African Union's commission chief Jean Ping condemned the "outrageous acts which undermine the efforts to stabilise the situation in Guinea-Bissau and tarnish the image of the country and Africa."

The AU called for the immediate and unconditional release of the two political leaders.

West African regional group ECOWAS, still grappling with a putsch and rebellion in nearby Mali, also condemned the coup, as did Nigerian President Goodluck Jonathan.

The coup leaders have already insisted they are not interested in power, stating that they acted because of an alleged "secret deal" with Angola, which has 200 troops in the country to help reform the military. They feared the Angolan force was secretly being built up.

Former colonial power Portugal, condemning the coup, rejected suggestions that there was anything untoward in the Angolan military presence.

In the days leading up to the coup, there had been fears of unrest in this former Portuguese colony, which has already suffered half a dozen coups or attempted coups since 1980.

The first round of the election had already been tainted by the assassination of former military intelligence chief Colonel Samba Diallo.

Diallo had been accused of involvement in a 2009 bombing that killed the then army chief and in turn prompted the murder of president Joao Bernardo Vieira in a revenge attack.

Since independence in 1974, Guinea-Bissau's army and state have remained in constant, often deadly, conflict, and no president has ever completed a full term in office. Three have been overthrown and one was assassinated.

The country has also become a hub for drug-running between South America and Europe.