The Russian bombardment has helped Syrian government forces recapture territory from rebel groups, but Islamic State (IS) still controls a third of Syria and Iraq.
One of their strongholds is Mosul in Iraq, where nearly two million residents have been cut off since 2014.
Some residents there are risking everything to escape.
Hundreds of yards into no man's land, Kurdish soldiers see movement in the dark.
But instead of IS fighters emerging from the darkness, it's a man and a teenage girl.
The man strips to his underwear to be searched, guarded by the Kurdish soldiers, who fear he could be a suicide bomber.
But these people have risked death to escape IS, walking for miles through the night. Now they're finally allowed to cross through a trench and into safety.
And then, one by one, come 12 more men -- some of them handing over guns.
It's an extraordinary sight because very few people have managed to leave Mosul after IS began sealing it off, stopping civilians from fleeing the city, and banning cell phones.
Overcome with relief, these men wanted to tell CBS News why they fled, but begged them to hide their identities, to protect family members still living in Mosul.
One man showed CBS News what he says are torture marks, from where IS miliants heated wire and used it to burn him.
His only crime was smoking, illegal under IS and its harsh interpretation of Islamic law.
Another man said he saw another Mosul resident beheaded after being caught with a cell phone sim card.
If they were caught during their escape, they faced a grim future. A man told CBS News three men were caught escaping recently, and IS hanged them in the street.
They're a criminal gang, cried one man, and we've been surviving on water and bread.
But IS is getting weaker.
When they first came they were tough, one man said, but now they can see that Mosul is turning against them.
The men told CBS News they plan to fight against IS themselves now they are free, and want to smuggle their wives and children out of Mosul as soon as they can.
Watch the video for the full CBS News report.