Northwestern Syria faces a "major protection crisis" with more than 3 million people trapped in a war zone, the United Nations warned on Monday.

"There is a major protection crisis in northwest Syria. That is the fundamental issue," Mark Cutts, the UN regional humanitarian coordinator for the Syria crisis, told reporters in Geneva.

"More than 3 million civilians [are] trapped in a war zone in the Idlib area, and the fighting has been forcing them into a smaller and smaller piece of land close to the Turkish border," he said.

He noted that even as refugees from Idlib flock towards the border, Turkey already hosts more refugees than any other country in the world, 3.6 million.

While Turkey had said it does not want to see more refugees coming in, he added: "Turkey also supports the cross-border humanitarian operation."

The UN is working very closely with Turkey to ensure that the border remains open.

"This a vital lifeline for the millions of people in northwest Syria," he said.


Fears of 'bloodbath'

The fighting is now getting "dangerously close" to the area where more than a million are living in tents and makeshift shelters in an "an extremely alarming situation" due to airstrikes and shelling, he explained.

Cutts said that if people continue to move into the area, "We are no doubt going to see a real bloodbath, a real massacre of civilians in that area."

Some 400,000 people were forced to flee their homes last summer, followed by a further escalation beginning in December, he said.

More than 900,000 people were forced to flee their homes.

"Since then, the numbers of displaced people are staggering. During the nine years of this war, about 12 million Syrians have been forced to flee their homes," he said.

About five-and-a-half million are refugees outside of Syria, and about six-and-a-half million are displaced inside the country.

"In northwest Syria, there are more than two-and-a-half million displaced people altogether, and that includes the 900,000 who fled in the last two months," said Cutts.

"So huge figures and a huge protection crisis. Our biggest concern is the widespread and systematic targeting of densely populated civilian areas," he said.


'Terrorized and traumatized'

Entire cities and towns and villages were emptied out, he said.

"Huge numbers of hospitals and schools and marketplaces and bakeries and water stations have been hit by airstrikes and shelling in the last few months.

"And there's a population now which is terrorized and traumatized and living in fear. People have been fleeing in fear, to the border area."

Idlib, near Turkey's southern border, falls within a de-escalation zone laid out in a deal between Turkey and Russia in late 2018.

The Syrian regime and its allies, have consistently broken the terms of the agreement, launching frequent attacks inside the territory where acts of aggression are expressly prohibited.

Turkey has called for an immediate halt to the attacks on Idlib, and for the cease-fire to be followed, warning that if the attacks do not stop, it will take action.