Syrian government warplanes pounded a suburb of Damascus on Sunday, killing at least 18 people and scattering shattered concrete blocks and mangled cars in the streets, activists said.

The Local Coordination Committees activist collective and the Britain-based Syrian Observatory for Human Rights said Sunday's air raids targeted the district of Douma northwest of the capital. President Bashar Assad's air force bombs Douma and other rebellious neighborhoods and towns around Damascus on a daily basis.

Observatory director Rami Abdurrahman said government jets carried out four strikes on Douma Sunday morning that killed 18 people and wounded more than 100. He warned the death toll could rise because many of the wounded were in critical condition.

The Local Coordination Committees said dozens of people were killed and wounded. It did not offer further details.

An amateur video posted online shows the moment of what the narrator says is the fourth strike. The roar of an airplane can be heard overhead, followed by a massive explosion. A huge column of gray smoke can then be seen rising over rooftops and television antennas.

Another video shows the aftermath: Rescuers clamber over a dusty pile of concrete blocks and twisted rebar in search of survivors as an ambulance siren wails in the background.

The videos appeared genuine and corresponded to other Associated Press reporting of the events depicted.