The Sudanese government has arrested the Islamist leader, Hassan Abdallah al-Turabi, and top members of his political party in the wake of an unprecedented attack by Darfur rebels in the vicinity of the capital, Khartoum.

Khalil Ibrahim, leader of the weekend raid on the city of Omdurman - which lies across the Nile River from Khartoum - was in the past a member of the Sudanese Islamist movement, the Sudan Tribune reported Monday. He is now better known for fighting the Sudanese government in Darfur as head of the Justice and Equality Movement (JEM).

The Tribune reported that hundreds of JEM rebels from Darfur clashed with Sudanese security forces on Saturday in what it called a "dramatic widening" of the conflict over Darfur, which is hundreds of kilometres from Khartoum and Omdurman. "TV footage showed pictures of burnt vehicles and dead bodies..." the Tribune reported.

It added that JEM spokesperson Ahmed Hussein said in an interview that the attack "sends a strong message to the regime whose president said publicly that he doesn’t want any POW’s or injured in Al-Fasher [the capital of North Darfur]."

The Sudanese government has reportedly offered a U.S.$125,000 reward for Ibrahim's capture. He was quoted Monday as telling Western news outlets that he was still in Omdurman, threatening to attack Khartoum, but Hussein told the Sudan Tribune he was back in Darfur.

Turabi is a former ally of Sudan's President Omar al-Bashir who served as justice minister and as speaker of the national assembly. He formed a new party, the Popular Congress Party, after breaking away from Bashir.