A video posted online in the name of Islamist group al-Nusra Front says it carried out two bomb attacks in the Syrian capital Damascus on Friday.
The attacks took place near a military intelligence building during the morning rush hour, killing at least 55 people.
The video says the bombings were in response to attacks on civilian areas by forces loyal to the President Bashar al-Assad, the BBC reports.
Opposition activists have accused the regime of orchestrating the explosions.
The al-Nusra Front emerged in January this year and has said it was behind previous attacks, including one on a police headquarters in March.