Robow’s defection comes after the United States in June cancelled a $5 million reward offered for his capture. His surrender is culmination of months of talks.

A renegade leader of Somalia’s Islamic extremist insurgents, al-Shabab, has surrendered to the government.

Mukhtar Robow arrived on Sunday in the government-controlled town of Hudur in southwestern Somalia, said Ahmed Mohamed, a senior government security official. He said Robow was airlifted from the Bakool jungle area where he and hundreds of his militia have been fighting al-Shabab since early last week.

Robow’s defection comes after the United States in June cancelled a $5 million reward offered for his capture. His surrender is culmination of months of talks between the Somali government and it is believed the cancellation of the bounty for his capture helped convince Robow to give himself up to the Somalia government.

Robow, who was the deputy director of al-Shabab, is the highest official to have ever quit the group. Estimated to be in his 50s, Robow is one of al-Shabab’s most experienced leaders, having traveled to Afghanistan and trained alongside al-Qaeda around 2000 after studies in Sudan. He had served as an al-Shabab spokesman, military commander and spiritual leader who planned and executed deadly attacks on Somali government troops and African Union peacekeeping forces, according to the U.S. Rewards for Justice program.

Al-Shabab last year was named the deadliest Islamic extremist group in Africa, with more than 4,200 people killed in 2016, according to the Washington-based Africa Center for Strategic Studies.

The extremist group has vowed to step up attacks after the recently elected government of President Mohamed Abdullahi “Farmajo” Mohamed launched a new military offensive against it. The group also faces a new military push from the United States after President Donald Trump approved expanded operations, including airstrikes. Al-Shabab still controls parts of rural Somalia.