On Tuesday, heavily armed men surrounded government buildings in the capital Bissau where President Umaro Sissoco Embalo and his prime minister were believed to be attending a cabinet meeting.

Embalo, 49, survived the attack. He later told reporters that he had been unharmed during a five-hour gun battle, which he described as a plot to wipe out the government.

The president added that several people had been killed in the attack but did not give a death toll.

On Wednesday, a military official who declined to be named told AFP that six soldiers had been killed.

He did not specify whether those killed had been defending or attacking Embalo.

Both the identity and the motives of the assailants remain unclear.

The army has established a commission to investigate the incident and find the perpetrators, according to the military official.

Guinea-Bissau is an impoverished and notoriously unstable coastal state of around two million people, lying south of Senegal.

It has suffered four military coups since independence from Portugal in 1974, with the most recent in 2012.

In 2014, the country vowed to return to democracy, but it has enjoyed little stability since and the armed forces wield substantial clout.

Guinea-Bissau also suffers from endemic corruption, and is known as a hub for cocaine trafficking between Latin America and Europe.