At least 384,000 people have died in Syria, including more than 116,000 civilians, since the war began in March 2011, the Syrian Observatory for Human Rights said Saturday.
Sparked by deadly repression of peaceful pro-democracy protests, the conflict has since turned into a complicated war involving opposition factions, militant groups and foreign powers.
As the war enters its 10th year, the regime of Bashar al-Assad now controls more than 70 percent of Syrian territory, thanks to the military support of its allies Russia, Iran and Lebanon's Hezbollah.
The conflict is the "worst man-made disaster since World War II," the United Nations human rights chief declared in 2017.
Idlib was one of the first provinces to join the uprisings against Assad, and is now the last to remain in opposition hands.
Despite a ceasefire agreed on March 6 between Turkey and Russia, few believe the Syrian regime will back off its plans to eventually retake the province.
