Gunfire erupted around the presidential palace in Gambia's capital Banjul overnight and soldiers blocked the bridge leading to the centre of the coastal city amid media reports of an attempted coup.
A diplomat said unknown gunmen had attacked the State House during the night but shooting had died down later.
Local diplomats and media said Gambia's President Yahya Jammeh was in France when the violence broke out.
Banks and other offices in the capital and surrounding neighbourhoods remained closed and residents locked themselves indoors. State radio played traditional kora music and did not refer to the incident.
A French foreign ministry spokesman said Mr Jammeh was not on an official visit in Paris and diplomatic sources said there was no indication that he was in France on a private visit either.
There was no official confirmation of reports on Twitter and media of an attempted coup but a senior West African diplomat told Reuters news agency that mutineers were in control of some strategic pockets of the capital on Tuesday afternoon.
A Bissau military officer has claimed forces loyal to the president have killed three alleged suspects behind the failed coup, including the ringleader said to be an army deserter.
The officer told AFP news agency the alleged coup plotters were led by an ex-army captain named Lamin Sanneh, adding that three were killed and one was captured.
Mr Jammeh, 49, who himself came to power in a coup 20 years ago, has stifled dissent in the tiny and impoverished West African nation and faced increased criticism from abroad over his human rights record.
In recent years, he has frequently reshuffled senior military and civilian officials, a policy that has prevented potential rivals accruing power, but has stoked instability.
