Several students are among at least 15 people killed in a bomb blast at a religious school in northern Afghanistan’s Samangan province, according to a local official.

Provincial spokesman Emdadullah Muhajir added that at least 20 others were also wounded in the explosion in the school in Aybak, the capital of Samangan, on Wednesday.

“A blast took place around 12:45pm inside Jahdia Madrasa in the center of the city.

Lots of boys are studying at this madrasa [religious school],” he said.

There was no immediate claim of responsibility.

Muhajir said an investigation had begun.

The federal interior ministry spokesperson Abdul Nafi Takor confirmed the blast but put the death toll so far at 10, with more injured.

“Our detective and security forces are working to identify the perpetrators of this unforgivable crime and bring them to justice,” Takor said.

A doctor in Aybak, about 200km (124 miles) north of the national capital Kabul, said the casualties were mostly youngsters.

“All of them are children and ordinary people,” he told the AFP news agency, asking not to be named.

Images and videos circulating on social media – which could not immediately be verified – showed officials picking their way through bodies strewn across the floor of a building.

Prayer mats, shattered glass and other debris littered the scene.