The Syrian crisis started in March 2011, when a government crackdown on peaceful protesters morphed into a nationwide uprising against the regime.

The LCC says more than 16,000 people have been killed in the conflict. The U.N. secretary-general said this week that almost 17,000 people have died.

The United Nations refugee agency says it has registered more than 120,000 refugees in neighboring Turkey, Jordan, Lebanon and Iraq.