GRAPHIC WARNING: Contains images which some viewers may find disturbing. (http://msnbcmedia.msn.com/j/MSNBC/Components/Photo/_new/pb-130221-damascus-da-04.photoblog600.jpg)SANA via APSyrian security agents next to a vehicle on fire following a huge explosion in Damascus on Feb. 21, 2013. (http://msnbcmedia.msn.com/j/MSNBC/Components/Photo/_new/pb-130221-damascus-da-02.photoblog600.jpg)SANA via EPAClouds of smoke swirling around destroyed cars following a large explosion in Damascus on Feb. 21, 2013. By The Associated Press
Syrian opposition activists said at least 31 people were killed in a car bomb attack in Damascus (http://www.nbcnews.com/id/50884744#.USYA66VA3gc) near the headquarters of the ruling Baath party and the Russian Embassy.
The Britain-based activist group Syrian Observatory for Human Rights said most of the dead were civilians, but that members of the Syrian security services were also killed in Thursday's attack.
Witnesses and opposition activists said the explosion targeted a security checkpoint central Mazraa neighborhood.
Syrian state TV also reported the blast, calling it a "terrorist" attack by a suicide bomber on a heavily populated area. Read more on this developing story (http://www.nbcnews.com/id/50884744).
EDITOR'S NOTE: Pictures released by the state-run Syrian Arab News Agency. (http://msnbcmedia.msn.com/j/MSNBC/Components/Photo/_new/pb-130221-damascus-da-01.photoblog600.jpg)SANA via EPAA thick black pall of smoke fills the air close to the site of a large explosion in Damascus on Feb. 21, 2013. (http://msnbcmedia.msn.com/j/MSNBC/Components/Photo/_new/pb-130221-damascus-da-03.photoblog600.jpg)SANA via APSyrian security agents carrying a body following a huge explosion that shook central Damascus on Feb. 21, 2013. (http://msnbcmedia.msn.com/j/MSNBC/Components/Photo/_new/pb-130221-damascus-da-05.photoblog600.jpg)SANA via APAn injured man lying on the ground after a huge explosion in Damascus on Feb. 21, 2013. (http://msnbcmedia.msn.com/j/MSNBC/Components/Photo/_new/pb-130221-damascus-da-06.photoblog600.jpg)SANA via EPADestruction following a large explosion in Damascus on Feb. 21, 2013. Slideshow: Syria uprising (http://slideshow.nbcnews.com/id/48244949/displaymode/1247/?wbSlideShowId=48244949&wbSection=news)(http://msnbcmedia.msn.com/j/MSNBC/Components/Slideshows/_production/ss-120719-syria-uprising/ss-130206-syria-tease.380;380;7;70;0.jpg) (http://slideshow.nbcnews.com/id/48244949/displaymode/1247/?wbSlideShowId=48244949&wbSection=news) / A look back at the conflict that has overtaken the country.Launch slideshowFollow @NBCNewsPictures (https://twitter.com/NBCNewsPictures)
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