“Despite the serious anomalies that marred the smooth running of the … election and in view of the results that came out of the ballot boxes, I am victorious in this election in the first round,” Diallo told journalists and cheering supporters.

He did not give any figures but said the tally was based on his party’s count, not an official tally being conducted by the national election commission, which has yet to publish results.

The electoral commission said Diallo’s claim carried no weight.

“The Independent National Electoral Commission is the only body authorized to give provisional results. It is neither for a political party nor for any individual to do so,” Mamadi 3 Kaba, a spokesman for the commission, told Reuters.

“We regret the attitude of Mr. Diallo and we say that this declaration is null and void,” he added.

Guinea’s government said in a statement late on Monday that Diallo’s statement was irresponsible and could sow confusion and undermine peace in the West African state. It warned it could launch criminal charges against him.

The government said results from over 15,000 polling stations were still being tallied. “It is impossible, at this stage of the process, to have neither trends, let alone the results of the vote.”

Diallo is the main challenger to Guinea’s 82-year-old incumbent president, Alpha Conde, who is seeking a third mandate after a constitutional change in March which sparked deadly protests.

Following his announcement, Diallo’s supporters swept into the streets in his strongholds, declaring their alleged victory.

Diallo said on Twitter that three young men were killed in the capital, and several others were injured by security forces while they celebrated his victory.

The government was not immediately available to comment on the deaths.

Security Minister Damantang Albert Camara earlier accused Diallo’s party of publishing false results, and warned it risked triggering violence.

“This strategy of forced, premature and unjustified celebration was carefully planned well before the election,” Camara said in a statement.

Rights groups say at least 50 people having been killed over the past year during demonstrations against the constitutional change that allowed Conde to seek at least six more years in power. (Reporting by Saliou Samb in Conakry; Writing by Hereward Holland and Bate Felix; Editing by Matthew Lewis, Hugh Lawson and Lincoln Feast.)