Key events in Syria's uprising
Here's a look at some of the key events in the Syrian uprising as the conflict marks its third anniversary:
March 2011 • Protests erupt in Daraa, Syria, over security forces' detention of a group of boys accused of painting anti-government graffiti on the walls of their school.June 2011• Police and soldiers in Jisr al-Shughour in northeastern Syria join forces with the protesters they were ordered to shoot,
Summer 2012• Fighting spreads to Aleppo, Syria's largest city and its former commercial capital. Over time, rebels seize control of about half of the city, but the battle there rages to this day.
June 2013• U.S. officials conclude that Assad's forces had used chemical weapons against the opposition. Obama authorizes direct support for the rebels.
August-September 2013 • A chemical weapons attack in the Damascus suburbs kills hundreds.
October 2013 • Syria destroys its chemical weapons production equipment. The number of Syrian refugees registered with the U.N. tops 2 million.
February 2014 • U.N. Peace talks in Geneva end without progress.
The Associated Press
Brahimi says: "I am very, very sorry, and I apologize to the Syrian people that their hopes which were very, very high that something will happen here."
March 15, 2014: The Syrian conflict marks its third anniversary.
See more about comments here.