Abbas al-Baqir Abbas was born in 1967 in Al-Dasis, located in the northern part of Al Jazirah, Sudan. Details about his early childhood are limited, but by adulthood, he had gained a reputation for religious fanaticism within his community. Reports indicated that his extreme ideology created tension within his family—his mother reportedly left their home because of his beliefs, and he had violently assaulted his sister, accusing her of infidelity.

Abbas studied economics at Tripoli University in Libya but was forced to leave the country after authorities linked him to Islamist activities that threatened national security. He later joined the Popular Defense Forces, a paramilitary group that fought rebels in southern Sudan, gaining combat experience during these campaigns.

Originally a member of Ansar al-Sunna, a pacifist Islamic movement in Sudan, Abbas became increasingly radicalized and broke away from the group. He eventually joined Takfir wal-Hijra, a militant extremist sect that advocated for enforcing Sharia law through violence and considered other Muslim groups apostates. Abbas repeatedly threatened members of Ansar al-Sunna with violence similar to a deadly 1994 mosque attack in Al Thawra, which had killed 19 worshipers.

Due to these threats and his known affiliation with Takfir wal-Hijra, Abbas was arrested in 1998 and detained for four months. A few months prior to the 2000 massacre, he was again arrested with 20 other suspected Takfir wal-Hijra members but convinced authorities that he had abandoned his extremist beliefs, leading to his release. Despite this, he continued harboring militant ideology and planned a major attack on a rival Sunni sect.

On December 8, 2000, during evening prayers around 9:00 p.m., Abbas al-Baqir Abbas carried out a brutal attack on worshipers inside the al-Sunna al-Mohammediyya Mosque in Jarafa, a village near Omdurman, Sudan. Armed with a Kalashnikov assault rifle, Abbas opened fire through a mosque window, deliberately targeting men and sparing women. Witnesses reported that he reassured a fleeing woman that he would not harm females before continuing his rampage inside the prayer area.

The massacre resulted in at least 22 people killed and more than 30 wounded (with higher death tolls reported by some sources, ranging up to 27 dead and 49 injured). Among the injured was a police officer who responded to the attack. Witness accounts suggested that gunfire came from multiple directions, leading some to believe there were other attackers, but police later confirmed that Abbas acted alone.

After the shooting, Abbas refused to surrender and engaged in a shootout with responding police units. He was ultimately shot dead at the scene, ending the massacre.

The day after the massacre, Sudanese President Omar al-Bashir visited the mosque to offer condolences and promised new legislation to combat extremist religious groups. Security forces launched a large-scale operation across Khartoum State, arresting 65 leading members of Takfir wal-Hijra. New emergency laws were passed, allowing authorities to detain suspected extremists for up to six months.

This massacre was part of a broader pattern of violence fueled by the ideological conflict between Takfir wal-Hijra and Ansar al-Sunna. Similar attacks had occurred in the 1990s, including a 1994 mosque shooting that killed 19 worshipers and other incidents throughout the decade.