Egypt's Grand Mufti Shawky Allam condemned Thursday's terror attack on Shubra el Kheima national security building.

In a statement Thursday, Allam said such terror attacks are carried out by groups stripped of faith and patriotism.

These groups seek to hamstring the nation's march of work and development, he said.

The mufti urged Egyptians to join hands in the face of terror and cooperate with security men to realize stability.

A shuddering explosion hit early Thursday the national security building in Shubra el Kheima, a Cairo suburb, leaving behind 29 people injured.

The blast left a two-meter deep and five-meter wide crater, causing an explosion of the main water pipeline.

An engineering commission inspected the building and said it was safe and needs only restoration.

The building's facade was cracked along with part of its fence.

Windows and doors of nearby buildings were smashed. About 20 nearby cars were also damaged.

Security forces sealed off all roads leading to the site of the blast and traffic was diverted.