DAKAR (Reuters) - The U.S. Embassy in Senegal said on Friday it had received information of a bomb threat to the capital Dakar.

In a text message to U.S. citizens, the embassy advised its nationals to stay away from the city centre until further notice but did not give any further details.

A Senegalese security source confirmed the threat and said the authorities had taken "necessary measures".

Reuters reporters in the city centre said there were signs of a reinforced police presence, but that people were going about their business ahead of Friday prayers.

The United States and African governments are backing a five-week-old French military campaign against Islamist rebels in Senegal's neighbour Mali.

Senegal has sent several hundred troops to join an African force being deployed to Mali. Islamists have threatened to strike back at anyone who supports the mission.

France, which has about 18,000 citizens in Senegal, said it did not have any information on a possible threat.

(Reporting By Ricci Shryock, Diadie Ba; and David Lewis and Nicolas Vinocur in Paris; Writing by John Irish; Editing by Stephen Powell)