KHARTOUM, Sudan - Sudan severed ties with Chad Sunday, accusing its neighbor of backing a rebel assault on the capital and raising the possibility of new border clashes that could worsen Darfur's humanitarian crisis.
A curfew was lifted in Sudan's capital but residents hunkered inside and security remained tight a day after the government repulsed an unprecedented assault on Khartoum by Darfur rebels.
In the capital's twin city of Omdurman, frightened residents emerged slowly to find buildings pockmarked with bullet holes and streets littered with charred cars. Women draped in flowered gowns stepped around huge armored personnel carriers, inspecting the damage. The city's main market was closed and residents milled around on side streets, staying off main roads lined with checkpoints.
"We were worried at first, that Khartoum may again be unsafe," said Hatem, a 45-year-old Omdurman resident who would not give his last name, fearing government reprisal. "We are extremely cautious."
"Police are searching for rebels on the run and are pestering us for IDs," he said.
A curfew was lifted in Khartoum but not in Omdurman, where police told state media that more than 300 rebels were arrested and many more had tossed away their camouflage uniforms to blend in with urban civilians.
State television paraded images of captured and bloodied fighters, including the body of a man it said was an aide to a top rebel leader. Army generals received congratulations in the streets and women praised them with traditional ululating screams.
But a leader of Darfur's Justice and Equality Movement, which carried out Saturday's attack, said his fighters were still in Omdurman and would ultimately bring down the Khartoum regime.
"The government didn't finish us off," JEM commander Suleiman Sandal told The Associated Press by telephone. He said he was in Omdurman. The call was interrupted several times as Sandal dictated orders to his fighters.
"We are dealing with all this military force with all our might," he said. "This was just practice. We promise to hit Khartoum one more time unless the (Darfur) issue is resolved," Sandal said.
For the first time ever, state TV broadcast a file photo of JEM leader Khalil Ibrahim, asking citizens to call a special hotline if they saw him. The government also announced a reward of $122 million for information leading to the Ibrahim's capture. By comparison, Washington has set a $25 million bounty on Osama bin Laden.
Sandal said Khalil was still commanding rebel fighters inside Omdurman.
"He is among us," Sandal said.
Saturday's daring attack was the closest Darfur rebels have ever come to Sudan's seat of government, hundreds of miles from their bases in the far west of the country.
Sudanese President Omar al-Bashir declared Chad to blame, and immediately cut ties with the neighboring country.
"These forces come from Chad who trained them ... We hold the Chadian regime fully responsible for what happened," al-Bashir said in a televised address, wearing military fatigues. "We have no choice but to sever relations."
Al-Bashir said he reserved the right to retaliate against Chad's "outlaw regime," raising the specter of a border war between the two countries who have long traded accusations over support for each others' rebels.
In February, Chadian rebels launched a failed assault on Chad's capital, and the country's president accused Sudan of supporting and arming the rebels. The Sudanese government denied any involvement, and the two later signed a peace agreement.
Sandal called JEM a national movement and denied that Chad was helping his group in its drive toward Khartoum.
Saturday night's assault — the first rebel offensive anywhere near the capital — puts greater pressure on the Sudanese government to deal with the situation in Darfur, where more than 200,000 people have died and 2.5 million have been chased from their homes since 2003. Sudan denies backing the janjaweed militia of Arab nomads accused of the worst atrocities in the conflict.
The instability on Sudan's western border has already spilled over into neighboring Chad, where the flow of rebels and refugees — many of whom share the same tribal lineage — over the remote border has destabilized both countries and strained relations.
Sudanese Interior Minister Ibrahim Hamed warned villagers on the Sudan-Chad border to beware of possible retaliatory attacks, and U.N. officials said security teams in Darfur were closely monitoring developments.
Any further clashes along the frontier would have grave consequences for the already ravaged Darfur region.
"This (attack) was an adventure... It complicates the situation in Darfur, considering that the attack put civilians in danger. It may lead the government to stop negotiations" with the rebels, said Mudawi Ibrahim, a Sudanese human rights activist who works in Darfur.
The attack weakened the rebels, who lost many fighters, and could lead to increased government support for Chadian rebels, he said.
Ibrahim had to call off a trip to Darfur with U.N. and European diplomats because of the security situation. "It will be hugely negative for humanitarian work," he said.
The JEM has become one of the most effective rebel movements in Darfur, where ethnic Africans took up arms against the government in 2003 to protest discrimination. In the last year it has expanded its operations into the neighboring province of Kordofan, even attacking oil installations.