A large bomb exploded in an area housing security and army compounds west of Umayyad Square in central Damascus on Thursday, opposition activists said. 

Groups Ahfad al-Rasoul and Ansar al-Islam said in a joint statement they planted bombs in a compound belonging to State Security in the area. 

Ansar al-Islam claimed responsibility for a bomb attack last month on the army's Chief of Staff headquarters in Umayyad Square, which started a large fire in the building. 

[Source: Reuters]