‘The cave’ in Idlib

In a field dotted with olive trees in embattled northwestern Syria, Shamseddeen Darra steps down into the gloomy underground shelter he and his family now call home.

After fleeing a deadly offensive by government forces on their home region of Idlib, they found nowhere else to go.

Beyond rolling hills in the village of Taltuna, Darra, his three brothers, their wives and more than a dozen children share a small room in the belly of the earth.

"We're living here for lack of a better option," says 35-year-old Darra, who calls their makeshift shelter "the cave".

"We didn't have any tents. We stayed in the town mosque for two days. We looked for a place to stay but found nothing," he explained.

After they found the abandoned shelter, dug out by villagers earlier in the civil war to hide from air strikes, they cleaned it out and moved in.

Backed by Russia, government forces have been chipping away at Syria's last major rebel bastion since December.

The region is run by jihadists and allied rebel groups, and is home to around three million civilians.

The violence has forced 900,000 of them to flee their homes or shelters, more than half of them children.

Inside their new underground home, Darra's children huddle on a carpet around a tray covered in small bowls of hummus and dried oregano in olive oil.

Sunshine seeps in only from the staircase, the only source of light to cast away the dank darkness.

In a corner, the family has piled its scant belongings under a red and navy blue blanket.

"We're suffering from the humidity. The kids are sick," he said, as nearby one of them started crying.

"And there are bugs," added Darra, wearing a thick black hooded sweatshirt.

Not far off, 40-year-old Abu Mohammed had also set up camp in an underground bunker.

He and around 40 people now share the space, where they have thrown a plastic rug on the ground and piled plastic jars of picked olives and other food along the uneven wall.

When we first arrived, "the cave was dirty. There was animal excrement," said Abu Mohammed, wearing a black leather jacket and sporting a greying beard.