KABUL- A blast tore through a mosque in the northern Afghan city of Kunduz, causing at least 20 casualties, the commander of Kunduz province said on Friday.

Qari Badri, the commander of Kunduz province, told Reuters 20 people had been killed or wounded in the blast on a Sunni mosque.

It was not clear who was behind the explosion which came after several blasts claimed by Islamic State rocked Afghanistan, including one in Kunduz and another on a Shi'ite mosque in Mazar-e-Sharif, the previous day.

(Reporting by Kabul Newsroom Editing by Raissa Kasolowsky)