Gunmen have killed seven people working on a strategic tunnel project in Indian-administered Kashmir and injured at least five others, officials say, in one of the worst attacks in the disputed region this year targeting civilians.

Police on Monday blamed the rebels fighting against Indian rule for what they called a “terror attack” at a camp for construction workers at Gagangir, near the resort town of Sonamarg.

Police said at least two attackers fired “indiscriminately” at officials and workers associated with the construction on Sunday night, killing two people on the spot. At least 10 others were taken to hospital, where five more died.

The attack came shortly after workers returned to their lodgings. The dead included five migrant workers and officials, one Kashmiri worker and a Kashmiri doctor.