At least nine people were killed and some 100 others injured after a car bomb exploded in the eastern Syrian city of Deir Ezzor on Saturday, al Jazeera television reported.
The blast took place in a parking lot near military intelligence offices, officials said.
State TV broadcast footage of the aftermath of the explosion, showing damaged buildings and smoldering cars.
The UK-based Syrian Observatory for Human Rights said it was followed by heavy gunfire.
It is just the latest in a string of deadly blasts which apparently targeted Syrian security agency buildings in the past few months.
A suicide suicide bombing in Damascus on May 11 killed 55 people in the worst attack on the city since the uprising against President Bashar al-Assad began in March last year.
State-run Ikhbariya TV described Saturday's explosion as a "terrorist attack."
However, Syria's main opposition coalition, the Syrian National Council, blamed the blast on the government.
"The Syrian National Council places on the Syrian regime the entire responsibility for the criminal bombings in several Syrian cities, including the one today in Deir Ezzor," the group said in a statement.
The bombing came as at least ten members of the Free Syrian Army in clashes with government troops in the northern city of Idlib.
