Fighting has escalated as insurgents captured Aleppo and nearby areas, and pro-govt Syrian and Russian forces are conducting airstrikes to counter the advances. We take a look at the key players involved in the conflict that began in 2011.

Islamist rebel group Hayat Tahrir al-Sham launched a lightning assault against pro-Assad forces in Aleppo. Here’s who else is fighting in Syria’s civil war.

The rekindling of fighting in Syria comes after a four-year lull in a civil war that first broke out in 2011. The uneasy stalemate among the country’s various hostile factions was broken when rebel fighters captured the city of Aleppo from President Bashar al-Assad’s regime and another rebel group took a smaller city north of there from Syrian Kurdish forces.

Syrian opposition forces in recent days seized Aleppo, one of Syria's largest cities, reigniting a 13-year civil war.

Syria's civil war has exploded back into life after Islamist rebels launched a lightning offensive on the northern city of Aleppo.

The Syrian government has lost control of the city of Aleppo, the country's second-largest, as opposition forces have made more territorial gains, a war monitor reported on Sunday. "The Syrian regime has completely lost control of Aleppo,