At least six people were killed after a cylinder exploded within the premises of District Headquarters Hospital on Monday evening, Geo TV reports.
More than 12 other people were reported injured in the incident.
DCO Attock Rana Akber Hayat confirmed that the deaths occurred after a portion of the hospital building collapsed following the blast.
Rescue services said the cylinder explosion damaged a portion of the woman's ward and multiple people are feared trapped in the rubble.
According to the police, two of the dead have been identified and two children are among the dead. Police officials added that the cylinder exploded in a three-room building.
DPO Attock Ibadat Nisar and federal minister Shiekh Aftab reached the area soon after the blast and ordered an inquiry into the blast.