Syrian refugees brave long journey to rebel-held areas after fleeing Lebanon

"We've been sleeping on the ground for two days, but we can't sleep at all.

How can we sleep on gravel, with the bitter cold at night and the scorching heat during the day?" says a Syrian refugee who fled Israeli bombardment in Lebanon, after a four-day journey to the rebel-held areas of northern Syria.

Lebanon became home to hundreds of thousands of Syrians since the 2011 deadly Syrian civil war.

But heavy Israeli air strikes on Lebanon have prompted more than 400,000 people, most of them returning Syrian refugees, to cross back into the war-torn country.