A leading opponent of Chad's ruling junta Yaya Dillo Djerou has been killed in an army assault on his party headquarters, a government spokesman said on Thursday.

Dillo died on Wednesday "where he had retreated, at the headquarters of his party. He didn't want to surrender and fired on law enforcement," Abderaman Koulamallah, who is also communications minister, said.

The prosecutor general earlier spoke of "dead including Yaya Dillo" without detailing the circumstances.

Dillo, who led the opposition Socialist Party Without Borders (PSF), was accused of having led an attack against the offices of the internal security agency overnight on Tuesday to Wednesday.

It came after the arrest of a PSF member accused of an "assassination attempt against the president of the supreme court".

Speaking on Wednesday, Dillo denied any involvement in the incident, denouncing the claim as a "lie" and politically motivated.
"I wasn't present," he said.

Dillo also condemned an attempted attack against the supreme court president as "staged".

On Tuesday, Chad announced it would hold a presidential election on May 6, which both transitional president Mahamat Idriss Deby Itno and Dillo -- who were cousins -- planned to contest.