Goz Beida: Anti-government rebels in Chad attacked the eastern town of Goz Beida on Saturday and heavy fighting was taking place there, an aid worker said.

Smoke was seen rising from the town and the sound of machine guns and heavy weapons could be heared.

Witnesses also said rebel fighters headed to the town in vehicles with machine-guns mounted on the back.

A Chadian rebel alliance fighting to topple President Idriss Deby has announced several of its columns are advancing westwards towards the capital N'Djamena.