KABUL, Afghanistan — An explosion killed at least 60 people during Friday Prayer at a mosque in eastern Afghanistan, local officials said. It is unclear who set off the blast.

The attack in Deh Bala, a small agricultural district in Nangarhar Province, caused the mosque’s roof to collapse, wounding at least 50 other people, said Mohammad Zahir Adel, the spokesman for public health in Nangarhar.

Attaullah Khogyani, a spokesman for the governor of Nangarhar Province, said that explosives had been stashed under a podium in the main atrium of the mosque where people were praying before they exploded.

The bombing follows what has been several bloody months in Afghanistan. The United Nations estimated that 1,174 civilians were killed and 3,139 wounded from July 1 to Sept. 30, a 42 percent increase from the same period last year, according to a report released on Thursday.