Insurgents have attacked a village in the northern Afghan province of Sar-e Pul, killing as many as 50 people, including women and children, according to officials.

The militants attacked a security outpost in the Mirza Olang area of Sayaad district overnight, torching 30 houses, Zabihullah Amani, a spokesman for the provincial governor, said on Sunday.

He said fighting was still going on but as many as 50 people, including children, women and elderly men, most of them members of the largely Shia Hazara community, may have been killed, according to village elders.

“They were killed in a brutal, inhumane way,” he said. Seven members of the Afghan security forces were also killed as well as a number of insurgents.

Many details of the attack, including the identity of the insurgents, were not immediately clear. Amani said they were a mixed group of Taliban and Islamic State fighters. However, the Taliban denied involvement, dismissing the claim as propaganda.

Although the Taliban and Isis are usually enemies, the allegiance of their forces is occasionally fluid, with fighters from both groups sometimes changing sides or cooperating with militants from other groups.

A senior government official in Kabul said that more security forces, including Afghan air force attack aircraft, were being sent to the scene.

Fighting has intensified this year across Afghanistan, with dozens of incidents recorded every day. In the first half of the year 1,662 civilians were killed and 3,581 injured, according to UN figures.