N'DJAMENA - Several people were hurt and some may have been killed in gunfire celebrating Chad's interim President Mahamat Idriss Deby's declared election victory on Thursday, an Amnesty International representative said, citing reports from partners.

Overnight, volleys of shots could be heard in the capital N'Djamena in the hours after the state election agency announced Deby had won a hefty 61.3% of the May 6 vote, even as his main challenger rejected the result and called for protests.

"Deaths and injuries from bullets have been reported ...The exact number of victims is unknown, but there is already talk of around ten dead, including children," Amnesty International researcher Abdoulaye Diarra told Reuters.

Reuters could not immediately confirm the number of casualties.

The chaotic celebrations followed a fraught electoral period marked by the killing of opposition figure Yaya Dillo, the omission of prominent opposition politicians from the candidate list, and other issues that critics say undermined the credibility of the vote.

N'Djamena was calm on Friday with little sign of the leading challenger Succes Masra's supporters taking to the streets. There was a heavy police presence including convoys of vehicles filled with men in camouflage fatigues patrolling the nearly empty streets.

On Friday, Masra's Transformateurs party, which has been keeping a parallel vote tally, said he had won, based on their count. "We have the evidence and Chadians all know it," the party said in an online post.

The presidential election makes Chad the first of the coup-hit countries in West and Central Africa to stage a return to constitutional rule via the ballot box, although Masra and other opposition factions have cried foul over transparency concerns.

Abdou Abarry, Special Representative of the U.N. Secretary General in Central Africa, called on all parties to show restraint.

  - Reuters