Dozens of activists from Chadian Prime Minister Succes Masra's party have been arrested accused of forgery and using false documents during this week's presidential election, a legal source told AFP Saturday.

The news came after officials declared junta leader General Mahamat Idriss Deby Itno the winner with 61.03 percent of the vote and after Masra himself had claimed victory.

N'Djamena prosecutor Oumar Kedellaye told AFP 76 activists with Masra's Transformers party had been taken into custody.

"They are being prosecuted for forgery, use of forgery, usurpation of title and complicity," he added.

The electoral code allows for the presence of candidates' delegates at voting stations, provided they have been accredited by the country's election agency ANGE.

Those arrested are accused of having forged access cards for different voting bureaus, said Kedellaye.

Sitack Yombatina, vice-president of the Transformers, denounced accusations they had interfered in the voting process as "ridiculous and fanciful".

On Tuesday, state television had reported the arrest of "suspected false delegates", all allegedly working for Masra's party.

On Wednesday, the party denounced what it called "arbitrary arrests" and "threats of serious violence" towards its supporters.

It also claimed its officials had been denied access to voting stations to observe the count.

Masra is a former fierce critic of Deby. Although Deby appointed him prime minister four months before the presidential election, Masra ran against him.

Masra, when he claimed victory on Thursday, had warned that Deby's team would rig the results and "steal the victory from the people", calling for peaceful protests.

The official count gave him 18.53 percent of the vote.

The country's opposition, which has been violently repressed and its leading figures barred from standing, had in any case dismissed him as a stooge, allowed to run to give the campaign a "democratic veneer".

Early in the campaign, observers predicted a massive win for Deby, 40, whose top rival was killed earlier this year.

Deby was proclaimed transitional president three years ago by his fellow generals after his father, iron-fisted president Idriss Deby Itno, had been shot dead by rebels after 30 years in power.