Guinea-Bissau has accused Portugal, the Community of Portuguese Language Countries (CPLP) and a former prime minister, of backing a coup bid after a gunbattle that claimed at least six 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 in the latest unrest to blight the chronically unstable country."The government considers Portugal, the CPLP and Carlos Gomes Junior as the instigators of this attempt at destabilisation,” a government statement, read out by 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 statement added.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 Carlos Gomes Junior, interrupting a presidential election between the first and second rounds, which he was leading after the first round. 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.In the hours after the raid, army vehicles criss-crossed Bissau, although the situation in the capital remained calm.