Columns of armed pick-up trucks

The rebels, whose columns of armed pick-up trucks have pushed westwards from the border with Sudan into eastern Chad here

Chad rebels at Ade

Chad accused Sudan's army of attacking Ade on its eastern border and blamed Sudan for Chadian rebel raids which have disrupted international aid operations . Ade is a frontier post in Chad's eastern Ouaddai region where Chadian rebels have attacked several towns in the last few days in a series of fast-moving hit-and-run raids.

The rebels fighting to topple Chadian President Idriss Deby said they had captured another eastern town, Am-Zoer, 70 km (40 miles) north west of Abeche. Abeche is the main hub of international aid operations in eastern Chad.

Chad described the rebels as Sudanese-backed "mercenaries."

"The Chadian army's reaction will be on a level with the impudence of the Sudanese regime," Chad's government said.

Spokesmen for the Chadian rebel National Alliance have said their ultimate objective is the capital N'Djamena, some 700 km (450 miles) to the west. Meanwhile, the United States moved all non-emergency staff from its embassy in the Chadian capital, N'Djamena, to Cameroon. here

Rebels in Moudeina and Ade

The Chadian government said "mercenaries paid by Sudan" had entered Chad's territory. Two Russian-made Mi-35 Hind attack helicopters and a larger, armed Mi-17 transport helicopter had set off from Abeche, the main city in the east of Chad, to target rebels in the area of Moudeina and Ade. Chad has a total of six helicopters, flown by Algerians and Ukrainians. Three were dispatched to Abeche in early April; the others are believed to be in Ndjamena. Upon returning to Abeche, one of the helicopters made "a hard and forced landing" at the airport, about 500 metres (yards) from a camp where a European Union force charged with protecting Darfur refugees is situated. Irish members of an EU protection force in eastern Chad said a helicopter had made a crash landing after being damaged by anti-aircraft fire. here

Chadian Army said to be at Ade on Sudan border