Ferdous Faramarz, spokesman for the Kabul police, said the mosque’s Imam was among the 12 dead and at least 15 other people were wounded. He did not identify the mosque where the blast took place.

There was no immediate claim of responsibility for the attack. Taliban insurgents have called a three-day ceasefire for the holiday, which marks the end of the Ramadan holy fasting month.

The blast came less than a week after an explosion at a school killed 80 people, most of them schoolgirls from the ethnic Hazara Shi’ite Muslim minority. The Taliban denounced that attack and no one has claimed responsibility for it. U.S. officials believe it may have been the work of a rival militant group such as Islamic State.

Violence, including attacks on civilians, have increased in Afghanistan, even as the United States has begun an operation to withdraw all its remaining troops over the next four months. (Reporting by Kabul newsroom Writing by Peter Graff; Editing by Andrew Heavens)