Chad's president fights back

N'DJAMENA (Reuters) - Troops loyal to Chad's president struck back at rebels besieging his palace on Sunday and the government said it repulsed an attack by Sudanese forces in the east that it called "a declaration of war".

In a conflicting version of the clash in the east, which opened up a fresh combat front, the rebels fighting to topple President Idriss Deby said they had taken the town of Adre on the border with Sudan's conflict-torn Darfur region.

In the capital N'Djamena, government helicopters and tanks defended Deby's fortified presidential complex against rebels in pickup trucks mounted with cannon and machine guns who stormed into the city on Saturday.

Rebel spokesman Henchi Ordjo said the army helicopters were operating from the French military base in N'Djamena, where he said President Deby was also sheltering. A base spokeswoman told Reuters it was "totally false" that Deby was there.

On the far eastern frontier, the army said it had beaten back a ground and air attack against Adre by a mixed force of Sudanese army troops and allied rebels and militia.

Deby's Minister of State for Mines and Energy, Gen. Mahamat Ali Abdallah Nassour, called the attack on Adre "a declaration of war" by Sudan.

Rebel spokesman Ordjo said Adre had been "liberated" by the rebel forces. He said the northern town of Faya Largeau had also been captured but there was no independent confirmation of this.

Sudan's government denied the accusations from its neighbor that it had backed the offensive by an alliance of Chadian insurgent groups, who denounce Deby as corrupt and dictatorial.

The rebel assault, the second to hit the Chadian capital in almost two years, sent France and other foreign governments scrambling to evacuate their nationals from the oil-producing central African country, which has a history of wars and coups.

CITY CUT BY FIGHTING

Radio France International quoted the medical charity Medecins Sans Frontieres estimating that several hundred people had been injured in two days of confused street fighting.

France Info radio said two French soldiers had been slightly hurt while protecting French and other foreign nationals.

Chadian officials blamed Sudan for the fighting, saying Khartoum was trying to sabotage the imminent deployment of a European Union peacekeeping force to eastern Chad that is tasked with protecting thousands of refugees and aid workers.

Residents in N'Djamena said heavy weapons and machine gun fire erupted before dawn near the presidential palace.

"The city is cut into two," said Reuters reporter Moumine Ngarmbassa in N'Djamena, adding it did not appear the rebels controlled all of the capital. "People are frightened that this fighting will go on," he said by phone.

Widespread looting was reported across the city.

Former colonial ruler France, which has a military force in Chad, said its planes evacuated more than 500 French and other foreigners to Gabon and were flying out several hundred more.

Aid group Oxfam said it evacuated its international staff from the capital and said the fighting could hamper humanitarian efforts for half a million people displaced in eastern Chad.

The United States said some of its non-vital embassy personnel had been flown to Cameroon.

France condemned the rebel assault, along with the African Union and the United States, but said it was staying "neutral".

But one rebel leader, Timane Erdimi, accused the French government of continuing to prop up Deby, a former French- trained helicopter pilot who came to power in a 1990 revolt.

"Instead of evacuating him and rapidly establishing relations with us, France persists in backing Deby," Erdimi said in an interview with the French newspaper Journal du Dimanche.

Several thousand Chadians and foreigners fleeing the fighting in N'Djamena streamed across the southwest border to Cameroon and Nigeria, local authorities there said.

The rebels failed in their last attempt to seize the capital in 2006. They say Deby, who won elections in 1996, 2001 and 2006, has squandered the country's oil resources, which are being developed by a U.S.-led oil consortium.

Chad was named the most corrupt country in the world, along with Bangladesh, in Transparency International's Corruption Perceptions Index for 2005.

(Additional reporting by Sudip Kar-Gupta in Paris, Opheera McDoom in Khartoum, Tansa Musa in Yaounde, Ibrahim Mshelizza in Maiduguri and Pascal Fletcher in Dakar; Writing by Pascal Fletcher; Editing by Michael Winfrey)