A Guinean court Saturday meted life sentences to two ringleaders of a failed assassination attempt on President Alpha Conde that rocked the nation just seven months after its first-ever democratic presidential election.

Another six defendants were handed jail terms of between five and 15 years after 17 hours of deliberation overnight by the court in the capital Conakry.

Around 60 people were arrested in connection with the attack on July 20, 2011, during which rogue soldiers opened fire on Conde's residence, blasting it with bazookas and rocket-propelled grenades in a two-hour gun battle.

The president was unhurt but a member of his presidential guard was killed and two others were injured.

A total of 31 civilians and soldiers had been charged with a variety of offences related to the incident, including criminal conspiracy, breach of state security, murder and attempted murder of the head of state.

Charges of attempted assassination against 17 alleged co-conspirators were dropped in March last year.

Conde said after the attack that he suspected it had been plotted in Dakar, with the knowledge of the Senegalese and Gambian governments, an accusation strongly denied by both administrations.

Guinea has a long history of coups and attempted coups, and as its first democratically elected president, Conde faces the huge task of turning around a nation plagued by decades of deadly political violence and ethnic gamesmanship.

He called parliamentary elections for September 24 on Thursday, bringing to an end a political deadlock of more than two years.

Legislative polls should have taken place within six months of Conde's inauguration in December 2010, but the vote was delayed with opposing factions unable to agree on how it should be staged, leaving the role of parliament to be played by an unelected National Transitional Council.

The last parliamentary elections in Guinea took place in June 2002 during the dictatorship of General Lansana Conte, who died in December 2008 after 24 years in power.