At least 15 people were killed and 55 others injured on Sunday when a bomb exploded in a crowded market in Parachinar, the capital of Pakistan’s Kurram district. The blast occurred in a Sunday market in the Shia-dominated north western tribal region of the country near the Afghan border, Al Jazeera reported.

It was not clear whether the blast was a suicide attack or a remote-controlled one, reported PTI. However, media reports said the explosion was carried out via a planted device and two suspects have been arrested.

A doctor at the hospital where the wounded were taken told AFP that most of the injured were in critical condition and said the toll could increase. No group has claimed responsibility for the attack yet.