Maneesh Bakshi, File, AP Photos
FILE - Justice and Equality Movement, JEM, leader Dr. Khalil Ibrahim listens during the Darfur Peace Talks, in Doha, Qatar, in this Feb. 11, 2009 file photo. Sudanese troops killed Khalil Ibrahim, the leader of the main Darfur rebel group, in fighting early Sunday Dec. 25, 2011 west of the capital Khartoum, the military said.

KHARTOUM, Sudan — The Sudanese army said it killed Khalil Ibrahim, the leader of the main Darfur rebel group, during fighting early Sunday west of the capital Khartoum, touting the death as a key victory over the rebels who had rejected a peace deal with the government.

The army said Ibrahim and several of his associates died during a military offensive in the North Kordofan state that was in retaliation for a rebel attack there Saturday, which authorities said had killed an undisclosed number of civilians.

Ibrahim led the Darfur-based Justice and Equality Movement, or JEM, which unlike other Darfur rebel groups did not join last year's peace deal signed with the Khartoum government.

An army statement, carried by the official SUNA news agency, said Ibrahim died in Wad Banda, an area in North Kordufan about 440 miles (700 kilometers) west of Khartoum. Ibrahim's group, JEM, could not immediately be reached for comment or confirmation of the Sudanese army claim.

Fighting in the area had flared up in the past days. On Saturday, the Sudanese army said the rebels from Darfur attacked three locations in neighboring North Kordufan, killing an unspecified number of civilians in an area where government forces were not present. JEM has not claimed responsibility for Saturday's attack, but in 2008, it was behind a large-scale attack on the capital.

The military said it responded Sunday to the rebel attacks, killing Ibrahim with a group of associates as they where retreating, allegedly toward South Sudan, which in July seceded from Sudan and became the world's youngest country.

Ibrahim was believed to have been living in exile in Libya, where he enjoyed the support of Moammar Gadhafi until the death of the Libyan dictator at the hands of the country's revolutionaries in October. After that, he reportedly returned to Sudan.

"The army cut all paths for the group as it was retreating and trying to cross into South Sudan to reorganize it forces," said Sudanese army spokesman Col. Khalid al-Sawarmy Saad. "Our gallant armed forces were able to kill rebel Khalil Ibrahim along with some of his associates."

"The armed forces laid a long chase and were able to impose an effective and complete siege against the remnants of Khalil Ibrahim's forces," added the spokesman, commending the residents of Wad Banda who "gave the ultimate example of patriotism" in the face of "bad treatment they received from the rebel forces. "

While Ibrahim's death is likely to be a significant blow to JEM, it is unclear what wider ramifications it would have in Darfur — Sudan's vast, mostly desert western region — or on the array of other Darfur rebel groups.

Darfur has been in turmoil since 2003, when ethnic African rebels accusing the Arab-dominated Sudanese government of discrimination took up arms against it. The Khartoum government is accused of retaliating by unleashing Arab militias on civilians — a charge the government denies. The U.N. estimates 300,000 people have died and 2.7 million have been displaced in the conflict.

Another prominent Darfur rebel group, the Sudan Liberation Movement, also was not part of the deal signed last year with Sudanese President Omar al-Bashir. The agreement, signed in Qatar and backed by the African Union, meant to provide a basis for a cease-fire, power sharing, equal distribution of wealth and compensation for displaced people.

Ismail el-Haj Musa, Sudanese deputy speaker of the council of states, told the pan-Arab Al-Jazeera TV on Sunday that Ibrahim had returned to Sudan sometime after Gadhafi's death and was en route south.

"He completely refused to come to the negotiating table, he never joined the peace talks," Musa said. "He committed acts against the state."