Blast tears through Sunni mosque in northern Afghan city Kunduz

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

Qari Badri, the commander of Kunduz province, told Reuters 20 people had been killed or wounded in the blast

It was not clear who was behind the explosion. Several blasts claimed by Islamic State hit the northern cities of Kunduz and Mazar-i-Sharif the previous day. One of them, at a mosque and another day earlier at a school in western Kabul, targeted the Shi'ite minority.

Afghanistan's Taliban rulers say they have secured the country since taking power in August, but international officials and analysts say the risk of resurgence in militancy remains.