Chad's President Idriss Deby has won a fifth term in office after winning 62% of the vote in elections earlier this month, official results show.
He has avoided a second-round vote, with his nearest rival, Saleh Kebzabo, taking 13% of votes cast.
On Tuesday, opposition parties said the vote counting lacked credibility.
Mr Deby, who took power in a coup 26 years ago, is seen by Western governments as a bulwark against Islamist militants in central Africa.
The headquarters of the regional multi-national force fighting Boko Haram insurgents is based in Chad.
The former French colony is also a base for France's military operations in Africa.
Mr Deby's supporters celebrated by firing guns into the air in the central square in the capital, N'Djamena.
Ahead of the announcement of the results late on Thursday, there was a strong military presence in the city, the AFP news agency reports.
During the 10 April election, there was an online blackout as access to the internet was cut and mobile phones were unable to send text messages.
Twelve candidates ran against Mr Deby and turnout among the more than six million registered voters was 71%, the electoral commission said.
Opposition politicians allege that hundreds of ballot boxes disappeared during the counting process.
Mr Deby has denied opposition claims that about 60 soldiers who voted against him have disappeared, the Associated Press news agency reports.
In the run-up to the vote, protest marches were banned and four activists campaigning against the president were given suspended sentences.