A powerful blast has torn through a packed mosque inside an Afghan army base in the eastern Khost Province as Friday Prayers were drawing to a close, killing at least 12 people, a local official said.

Talib Mangal, a Khost governor spokesman told RFE/RL on November 23 that "according to initial estimates" another 33 people were wounded in the explosion.

Some news agencies put the deaths toll at 26, citing Afghan officials who said more than 50 others were wounded in the attack.

No group claimed responsibility for the assault that targeted soldiers offering prayers.

"There were soldiers lying everywhere and the smoke was so thick, it was difficult to see," Abdullah, a spokesman at the base, told the Associated Press news agency.

It wasn't immediately clear whether the attack was carried out by a suicide bomber.

Afghan President Ashraf Ghani condemned the attack, calling it "anti-Islamic and inhumane."

In a statement, Ghani urged a swift investigation into the bombing and said he wanted to know how security at the army base was breached, calling for those responsible to be punished.

The attack comes just days after a suicide bomber targeted a gathering of religious scholars in the capital, Kabul, killing at least 50 people and wounding more than 80 others.

In another development in Afghanistan on November 23, hundreds of protesters blocked a key highway, denouncing the deaths of three local residents, including a child, in an operation against militants.

Parwan police chief Muhammad Mahfuz Walizada told RFE/RL that the operation overnight by Afghan and international forces in Jebul Siraj district targeted a local warlord, but killed the other people by mistake.

Carrying the bodies of the dead, the protesters blocked the Kabul-Salang highway for several hours.

With reporting by Reuters, AP, and AFP