Some witnesses in the city's Kipe district said they heard heavy weapons fired by the military for more than two hours, subsiding around 5:30 am.

Police had closed off access to the administrative centre of the city, at Kaloum, witnesses said.

Conde became president in November last year, taking over from a military junta after the coup-wracked West African country's first democratic election since gaining independence from France in 1958.

Guinea has a long history of coups and attempted coups, the last coming in December 2008 when a young army officer, Captain Moussa Dadis Camara, seized power. He was overthrown a year later after being shot in the head by a close aide.

A transition government led by General Sekouba Konate led the country to its first democratic elections in November last year.

Copyright AFP (Agence France-Presse), 2011