An attack rocked a Shia mosque in Kandahar, Afghanistan killing at least 33 people and wounding 73 more according to local health officials.

The blast occurred at the city’s Bibi Fatima mosque, the largest mosque for Shia worshippers, as people were gathering for prayers. One eyewitness told the AFP news service that the mosque was hit with three explosions. One at the mosque’s main door, another at a southern area, and a third where worshippers wash prior to entering.

However, another eyewitness told the Associated Press that the mosque was attacked by four suicide bombers. He said that two detonated suicide vests at the main security gate, allowing the other two to enter the mosque where they detonated their explosives among the gathered worshippers. The mosque is generally attended by 500 people.

Qari Saeed Khosti, the Taliban’s Interior Ministry spokesman, said that authorities were collecting details of the explosion.