Mahsum, a native of Shule (Kunixar) County, became involved with the East Turkestan independence movement early in his life; in his late 20s, he was already a lecturer at a training camp in Yecheng County, preaching Jihad and advocating the use of violence against Chinese authorities. He was arrested in October 1993 by the Chinese police for terrorist activities and sentenced to three years of re-education through labour. After fleeing China in 1997 to Mecca, Mahsum joined the Taliban and lived in Afghanistan and Pakistan; he held an Afghan passport issued by the Taliban. In early 1999, he was said to have met with Osama bin Laden, who offered him US$300,000 of financial assistance for the East Turkestan Islamic Movement in the following year; Mahsum himself denied any connection with bin Laden. The Chinese government has accused him of directing a series of violent terrorist activities including robbery and murder in Ürümqi on February 4, 1999 and violent murders in the Khotan region on December 14, 1999; it is believed that these attacks were carried out by an operative of his named Mutalif Kasim.