At least 26 people were killed in an explosion during Friday prayers at a mosque in the eastern Afghan province of Khost.
A security official said the mosque was on an Afghan army base in the province's Ismail Khel district.
All those killed in the suicide attack were working for the Afghan security forces, said Captain Abdullah, a military spokesman in Khost, who goes by only one name.
The Taliban, who are waging a war to oust the western-backed Afghan government and expel foreign forces from Afghanistan, 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 insurgents.
The blast comes just days after more than 50 people were killed when a suicide bomber struck a gathering in Kabul of religious leaders, scholars and worshippers of the Sufi sect of Islam to mark the Prophet Mohammed's birthday.
There was no claim of responsibility for the attack but it was condemned by the Taliban.
More to follow
