(CNN) -- An explosion ripped through a northern Pakistan mosque where people had gathered for evening prayers Thursday, killing eight people -- including a child -- and injuring 67 others, officials said.
The incident occurred in the city of Peshawar, the minister of health in the region, Shaukat Yousafzai, told CNN. A child was among those killed, according to officials at Peshawar's Lady Reading Hospital.
The blast was under investigation, though police and intelligence officials said they believed it was caused by a bomb. The explosion happened at the start of what was supposed to be an overnight service in which congregants were to attend evening prayers, listen to a nighttime sermon and sleep there.
Also Thursday, an undetonated bomb was found in a mosque in Nowshera, about 50 kilometers (30 miles) east of Peshawar, police said.
People found the bomb in a tin container near the mosque's entrance before evening prayers and notified authorities, police said. A bomb disposal unit defused the device, police spokesman Turk Ali Shah said.
Pakistan, where militants have a strong presence, has long been beset by violence.