The bomb blast happened en route a Pakistani security forces’ vehicle in Orangi Town area of Karachi, the capital of southern Sindh province, Pakistani-based Dunya News reported.
According to the report, four Pakistani military forces and a senior Pakistani officer were killed in the incident.
The incident took place while Pakistani security forces were stationed at a checkpoint when they were suddenly attacked by gunmen on a motorcycle.
The unidentified gunmen fled the scene of incident after the crime.
No group or individual has so far claimed responsibility for the blast.