At least four policemen were injured when a bomb hit a police check post in Pakistan's southern port city of Karachi on Wednesday morning, officials said.
Senior Superintendent Police (SSP) Pir Muhammad Shah said that some unknown militants hurled a hand grenade at the police check post from a bridge near which it was located, and fled the scene.
He said that there were not many cops at the check post as the policemen on night duty left the place, and fresh contingent was still on its way when the incident happened.
The SSP said that the blast left several motorbikes and the check post badly damaged.
The injured policemen have been shifted to a nearby hospital.
The attack came at about 9:30 a.m. local time in Shahrah-i- Faisal area of Karachi, the capital city of the country's southern Sindh province.
No group has claimed responsibility for the attack yet.
Police cordoned off the area for investigations. ISLAMABAD, Sept. 3 (Xinhua)