ABIDJAN, Feb. 18 (Xinhua) -- Explosions and bursts of gunfire were heard in the direction of the Presidential Palace in Niger's capital Niamey on Thursday afternoon, an incident many suspected to be a coup attempt to topple President Mamadou Tandja.

Xinhua's correspondent reported at the scene that fierce shooting lasted between midday (1200 GMT) and 2:00 p. m. (1400 GMT) . Several people were injured in the fighting and sent to a hospital in Niamey.

Speculation is running high about where the 72-year-old president is, with some reports saying he was captured by a group of soldiers.

In another development, France has advised its citizens not to travel to Niger while warning those in Niamey to stay indoors. There are about 1,500 French citizens living in Niger and 500 Europeans in Niamey, according to Paris.

President Tandja, who has been elected twice since 1999, managed to amend the constitution last year in search for a third term of office.

The African Union and the Economic Community of West African States saw the move as unconstitutional and suspended Niger to press it to return to the constitutional order.

Niger, a former French colony, gained independence in 1960. On April 9, 1999, President Ibrahim Bare Mainassara was assassinated. His successor, Major Daouda Malam Wane, led a transitional government until an election was held and won by Tandja in December 1999. A former army colonel, Tandja is a member of the Kanouri minority from the region bordering Chad.