Khartoum, Sudan ? Hundreds of rebels from war-ravaged Darfur clashed with Sudanese security forces on the doorstep of the capital Saturday in a dramatic widening of the five-year-old conflict.

It was the first foray into the seat of the Sudanese government by a rebel group once confined to the western region, which is deeply scarred by the struggle between the ethnic African rebels and the Arab-dominated central government.

The country’s interior minister said government forces successfully “chased” away the rebels by nightfall, about three hours after the first outbreak of violence, and killed a rebel leader and his aide. State television showed footage of the fighters in handcuffs and soldiers driving confiscated jeeps through empty streets, saluting colleagues standing at attention.

But a rebel leader denied his fighters suffered heavy casualties and said some took up positions inside Khartoum, while others remained in its twin city, Omdurman.

“They will continue their mission,” rebel spokesman Ahmed Hussain told The Associated Press. “They successfully destroyed a lot of tanks.”

TV footage showed burning trucks, smoke billowing over Omdurman and at least two bodies sprawled in a dusty street and slumped in the front seat of a convertible jeep.

“I saw dead people in the streets and cars burned,” said Hatem, an Omdurman resident who refused to give his last name fearing government reprisal. He said most of the victims wore turbans distinctive to rebel areas.

Hatem said he sought cover at a friend’s house while bullets and tank shells whizzed through the city. “They had many weapons and explosives,” he said by telephone.

With just a few thousand members, the Justice and Equality Movement is outnumbered by and far less equipped than Sudan’s military, believed to be more than 100,000 strong, but the group still represents the most significant military threat to the Sudanese government in Darfur.

Residents and government officials said it appeared that JEM had been repelled or retreated from Khartoum’s edge late Saturday. But the scale of the government’s initial reaction – deploying heavily on residential streets, setting up checkpoints, imposing an overnight curfew – suggested Sudan’s powerful military was shaken by the assault.

“Militarily they can’t succeeded. But they can put everyone on notice,” said Eric Reeves, a Sudan researcher and analyst at Smith College. He said the rebels’ aim was to spread panic in Khartoum and through the army ranks, stir up opposition to the government and draw attention to their fight in Darfur, some 620 miles from the capital.

“It brings a lot of pressure to bear on the regime,” Reeves said.

The clashes came after days of government warnings that JEM planned to target Khartoum. Troops cut off access to bridges linking Khartoum to Omdurman, and armored vehicles patrolled streets. The government later extended a curfew, saying some rebel members shed their uniforms and could be hiding among civilians. Residents reported power outages in Khartoum.

In Washington, a spokesman for the National Security Council said the Bush administration was concerned and monitoring the situation.

“We urge both sides to cease hostilities, whether it is the rebel group or the government,” said spokesman Gordon Johndroe. “We want to see calm and order restored.”