Guinea-Bissau has accused Portugal, the Community of Portuguese Language Countries and a former prime minister of backing a coup bid after a gun battle that claimed at least seven lives.
Gunmen staged a pre-dawn raid on the barracks of an elite army unit near the capital's airport on Sunday, sparking a firefight - the latest unrest to blight the small, chronically unstable West African country.
Witnesses said the raid had been led by Captain Pansau N'Tchama, the head of a commando unit that assassinated president Joao Bernardo Vieira in 2009. It was not immediately clear why N'Tchama might have carried out the assault. But the captain is a former associate of the government overthrown in an April 12 coup.
That coup toppled the government of Gomes Junior, interrupting a presidential election between the first and second rounds, which he was leading after the first round.
"The government considers Portugal, the CPLP and Carlos Gomes Junior as the instigators of this attempt at destabilisation," Communications Minister Fernando Vaz said.
Its aim had been to overthrow the transitional government, undermine the political process, bring Gomes Junior back to power and justify an international "stabilisation" force, the minister added.
In Sunday's raid, the gunmen launched an assault on the "red beret" barracks at about 4am.
The soldiers there fought off the attack after about an hour of fighting, forcing the assailants to flee, witnesses said.
N'Tchama is a former member of the "red berets" and returned last week from Portugal, where he had been undergoing military training since July 2009, security sources said.
A journalist at the scene saw the corpses of six attackers. One soldier said that a sentry at the barracks had also been killed by N'Tchama himself.