Sudan cuts ties with Chad

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.