Tandja was the favourite to win after gaining widespread backing

He won 65.5% of the votes in the run-off ballot, comfortably defeating the socialist opposition candidate Mahamadou Issoufou, who polled 34.5%

Mr Tandja, a 66-year-old former army colonel, was the favourite to win, having won the support of four of his five opponents after the first round.

The vote was deemed by international observers to have been free and fair.

Political stability

Just under 45% of around 5.3 million registered voters took part in the 4 December run-off.

Six candidates stood in the initial round on 15 November, in which Mr Tandja failed to win a clear majority of the votes.

Issoufou was also beaten by Tandja in a run-off in 1999

Observers from the International Francophone Organisation said in a statement: "Freedom and privacy were guaranteed. The organisation and counting of ballots were carried out according to the rules."

Mr Tandja is the first president to have made it through a full term in office since democratic elections were first held in 1993.

His three predecessors were either ousted or assassinated, the last in 1999.

Correspondents say Mr Tandja has brought a measure of economic and political stability to Niger.

However, two thirds of Niger's 11 million people live on less than a dollar a day and the country is at the bottom of the UN Human Development Index.