A national security building in northern Cairo was hit by a car bomb blast targeting security forces in the early hours of Thursday morning, according to Egypt's Interior Ministry. Six policemen were injured in the attack, which took place in the Shubra district of Cairo. No casualties have been reported yet. The injured were rushed to a nearby hospital, according to BBC News.

The explosion struck the headquarters of the National Security Agency, the country's domestic spy service. The driver of the car parked the vehicle rigged with explosives outside the building and escaped on a motorcycle before the bomb detonated, The Washington Post reported.

"A man suddenly stopped his car in front of the state security building, jumped out of it and fled on a motorbike that followed the car," said the Interior Ministry, according to The Guardian.

The blast could be heard across several neighborhoods in city at approximately 2 a.m. (midnight GMT) rattling windows and waking sleeping residents miles from the blast site.

The blast caused a crater in the street and partially damaged the security building. Locals reported seeing glass from the blown-out windows scattered across several streets in the area.

The incident takes places amid growing concern of an increasingly brazen insurgency that has carried out a series of attacks in Cairo. Last month, a car bomb blast near the Italian consulate in Cairo killed one and injured nine others, as HNGN previously reported.