Chad rebels say will accept ceasefire if Deby quits

N'DJAMENA (Reuters) - Chadian rebels said on Tuesday they would agree to a ceasefire only if President Idriss Deby steps down.

They also accused France of intervening directly in the fighting in Chad with helicopters and tanks in support of Deby's troops, and of causing civilian casualties.

"We're for a ceasefire if mediators can find a solution in which President Idriss Deby is separated from power," rebel spokesman Henchi Ordjo told Reuters by phone.

He said he was speaking from somewhere in the capital N'Djamena, which was attacked by rebel forces at the weekend.

Rebel leaders say their forces pulled back from the city, but are close by. Deby's government said it had driven them out.

"Deby must be moved aside," Ordjo said.

Ordjo said French helicopters and tanks, part of a French military contingent stationed in Chad, had opened fire in fighting near N'Djamena's airport on Monday. "France has involved itself directly in the conflict ... they've caused civilian victims," Ordjo said.

The capital was reported generally calm on Monday, but helicopters had flown overhead and some explosions and shooting were heard, residents said.

There was no independent confirmation of this accusation and France has in the past strenuously denied rebel assertions that its forces took part in direct combat against rebel forces.