A suicide blast at a mosque in an army base on Friday killed at least 26 people and wounded 50, security officials in the area said.
However, there was no immediate claim of responsibility for the crime.
One security official said the victims had gathered for Friday prayers at the mosque in the Ismail Khel district of Khost province, in eastern Afghanistan.
All those killed in the suicide attack were working for the Afghan security forces, said Capt. Abdullah, a military spokesman in Khost, who goes by only one name.
Friday’s attack came three days after a suicide bomber detonated his explosives at a gathering of religious scholars in Kabul, the capital.
Officials said 55 scholars marking the birthday of the Prophet Mohammad were killed and more than 90 injured in the blast in a banquet hall.
The Talibans are waging a war to oust the Western-backed Afghan government and expel foreign forces from Afghanistan.
The Talibans have launched a series of high-profile attacks against Afghan security forces in recent weeks.
Hundreds of Afghan security guards have been killed, their checkpoints destroyed and weapons seized by the hardline Islamist fighters.