Some humanitarian flights into Goz-Beida were cancelled on Friday.
REBELS SAY THEY ADVANCING
Leaders and spokesmen of the anti-Deby insurgent National Alliance said in statements to foreign media a powerful rebel force was advancing westwards towards the capital N'Djamena.
One rebel spokesman had said the rebels were prepared to call off their offensive if France and the European Union forced Deby to agree to round-table talks on Chad's political future.
In early February, rebel columns raced from the east to attack N'Djamena in a lightning raid which sent Western governments, including former colonial power France, scrambling to evacuate their nationals from the city.
Several hundred people were killed in intense fighting before the rebels pulled back after France's government and military moved to strongly support Deby, who himself seized power in an eastern revolt in 1990.
France has military aircraft and troops stationed in Chad under a defence cooperation treaty, in which Paris provides intelligence, logistical and medical help to Chad's government.
A fresh Chadian rebel offensive against Deby had been widely expected since Sudanese Darfuri insurgents attacked the Sudanese capital Khartoum in May.
Both countries accuse each other of supporting rebel groups hostile to each others' governments.
Chad's President Deby and his Sudanese counterpart Omar Hassan al-Bashir signed a non-aggression pact in Senegal in March on the sidelines of a summit of Islamic nations.
But the pact - the latest in a string of failed peace deals between the two feuding neighbours - soon collapsed amid mutual accusations of cross-border violations.
