Attackers set off a car bomb near the office of the Save the Children aid agency in the eastern Afghan city of Jalalabad on Wednesday and clashed with security forces, according to a provincial government spokesman.

The provincial health department said 11 wounded people had been taken to hospital. There were several other aid groups and government offices in the immediate area, raising the possibility that Save the Children was not the target.

No group had claimed responsibility for the attack. But Jalalabad, in Nangarhar province, is near the porous border with Pakistan. The province has become a stronghold for Islamic State, one of Afghanistan’s most dangerous militant groups.