Ugandan officials say the fugitive leader of a Ugandan rebel group operating in eastern Congo has been arrested in Tanzania, ending years of a manhunt.

Ugandan police spokesman Fred Enanga said Thursday that authorities believe Jamil Mukulu, who had been on the run since the 1990s as leader of an Islamic extremist group known as Allied Democratic Forces, is in the custody of Tanzanian security officials.

A Ugandan security official confirmed Mukulu had been positively identified with the help of a relative in Uganda, after photos of the man in custody were shared between Ugandan and Tanzanian officials.

The ADF is one of many armed groups operating in eastern Congo, and the U.S.-sanctioned Mukulu had been the subject of an Interpol arrest warrant.