The mosque, in the city of Khost, was also being used as a voter registration center, ahead of parliamentary elections in October.
The blast was caused by a bomb placed in the mosque, rather than by a suicide bomber, Khost’s Chief of Police Basir Bina told CNN.
The Taliban denied involvement in the blast, and so far no group has claimed responsibility for the attack, which happened at 2:20pm local time.
Among the dead was Agence France Presse photographer Shah Marai, a father of six and chief photographer in the agency’s bureau there. He had covering the Afghan conflict for over 15 years.
ISIS claimed responsibility for the attack.
An especially violent day
That day, a suicide bomber in Kandahar Province, southern Afghanistan, also killed 11 students at a local religious school. So far, no group has claimed responsibility for the attack.
Several members of the Afghan security forces were also killed in the operation, according to the US Department of Defense.
Fighting the Taliban
Those reports came on the heels of an Afghan government announcement in February that it would be willing to recognize the Taliban as a legitimate political party, as part of a potential ceasefire agreement with the Islamist militant group.
The Taliban has been waging a bitter fight in Afghanistan with the ultimate goal of ruling the country and imposing its strict interpretation of Islamic law.
The group controlled Afghanistan until 2001, when it was overthrown by the US-led coalition that invaded the country following the 9/11 attacks.
Source : Nbcnewyork