Chad President Idriss Deby has won a fifth term in office, soundly defeating more than a dozen challengers to remain leader of a country that is central to Africa's fight against Islamic militants, the national election commission announced late Thursday.

Deby earned 61.5 percent of the April 10 contest for which more than 6 million voters were registered, according to provisional results that need to be ratified by the Constitutional Council. He needed more than 50 percent to avoid a runoff. The turnout was 76 percent, the election commission said.

The announcement came one day after a visit by Samantha Power, U.S. envoy to the United Nations, and top U.S. military officials that highlighted Chad's prominence in the fight against Islamic extremist groups such as Boko Haram. The country serves as headquarters for a five-nation regional force intended to wipe out the Nigeria-based group, which has launched multiple attacks on Chadian territory including suicide bombings in the capital, N'Djamena.

Chad is also the base for France's military operations in Africa.

Deby appeared before hundreds of supporters in the capital just after the commission's announcement, thanking them for the win while urging them to wait for the Constitutional Council's ratification. "It's your victory," he said.

Earlier this week, the opposition withdrew from the electoral commission, citing doubts the vote would be credible.

During her visit Wednesday, Power expressed displeasure with a "crackdown on freedom of protest" and a government decision to shut down the Internet and text messaging throughout Chad for several days around the time of the vote.

In a rare appearance before foreign journalists at his presidential palace, Deby denied opposition claims that some 60 security forces who voted against him have disappeared.

-AP