Syria’s civil war: key facts, important players

Syria's turmoil began with protests against President Bashar al-Assad's regime in March 2011. It crossed an important threshold a year and a half later, when the international Red Cross formally declared it a civil war.

The casualty tallies continue to climb higher as fighting rages across the country. Tens of thousands are fleeing Syria, seeking sanctuary in refugee camps in neighbouring countries. See how the conflict has escalated and who the key participants are in this troubled country.