ATTOCK, June 24: An awaited nod of approval by the Punjab government is delaying the investigation into an explosion near Burhan area that killed three labourers and seriously injured four others a fortnight back, it has been learnt.

The Hassanabdal Saddar police registered a case of criminal negligence against a construction firm engaged in work on the Islamabad-Peshawar Motorway for storing explosives inside the camp without following prescribed rules.

However, SHO Inspector Raja Shakeel told this reporter that investigation into the incident was still pending as the exercise could not be carried out without the approval of the Punjab home department.

“A letter has been sent to the home department through the District Police Headquarters Attock to seek permission for starting the investigation, however, no reply has been received so far,” Inspector Shakeel said.