Activists say large explosion hits Syrian intelligence building in Aleppo

In this Tuesday, Oct. 2, 2012 file photo, smoke rises over Saif Al Dawla district, in Aleppo, Syria. AP Photo/Manu Brabo

BEIRUT – Two Syrian activist groups say a large explosion has struck a government intelligence building in the northern city of Aleppo.

The Aleppo Media Center and the Britain-based Syrian Observatory for Human Rights both say the massive blast that hit the Air Force Intelligence building was followed by intense clashes in the area.

The Observatory said Wednesday’s attack began with the rebels detonating explosives placed in a tunnel dug under the security branch.