At least 49 people were killed when a bomb went off at a mosque in southern Pakistan on Friday.

The Associated Press reported that the explosion occurred at a Shi’ite mosque in the city of Shikarpur and the Sunni militant group Jundullah has claimed responsibility for the blast.

"Our target was the Shia mosque ... They are our enemies," said Fahad Marwat, a Jundullah spokesman.

Hadi Bakhsh Zardari, the deputy commissioner of the district said that in addition to the deceased, dozens more were injured and transported to an area hospital.

Reuters noted that local police said it is not yet clear if the blast was caused by a suicide bomber or an explosive device that detonated when the mosque became crowded.

The latest attack comes after gunmen stormed a Peshawar school in December and killed more than 150 people, mostly children, in one of the deadliest attacks the country has seen. And earlier this month, in the city of Rawalpindi, six people were killed and 17 others were wounded by a suicide bomber outside a Shi'ite mosque.