Almost three-quarters of a million Syrians have been forced out of their homes by fighting in the first months of 2018, according to the senior UN official coordinating the crisis response.

With growing anticipation that retaliatory US strikes may be launched imminently in response to the latest suspected use of chemical weapons in Douma, Panos Moumtzis, regional humanitarian coordinator for the country’s crisis, issued a bleak picture of continuing large-scale displacement.

“I am deeply concerned about the continuing massive displacement of close to 700,000 Syrians since the beginning of the year due to ongoing hostilities in the country,” Moumtzis said in a statement.

Moumtzis added that the figures are in addition to the 6.5 million people already internally displaced, and the more than 5.6 million Syrian refugees in neighbouring countries.

Describing a humanitarian situation where more than half of Syria’s population had now been forced to flee, he said: “Civilians in Syria continue to be caught up in horrific violence. Hostilities, including attacks on residential areas, civilian infrastructure, including hospitals, markets, schools … have resulted in scores of civilians being killed or injured on a daily basis.

“This is unacceptable. Humanitarian organisations continue to call for minimum protection standards around civilian evacuations to be respected, including in relation to unconditional access to humanitarian assistance and protection of humanitarian workers.”

According to UN figures, the totals include those displaced from around Idlib, where more than 400,000 people have reportedly been uprooted by recent military operations, including more than 300,000 in Idlib itself and 137,000 from Afrin.

Also displaced in the first months of 2018 have been large numbers of people fleeing largely rural areas around Damascus.

“The crisis has also dramatically deepened for hundreds of thousands of people in rural Damascus following a devastating offensive on eastern Ghouta,” said Moumtzis.

He added that since mid-February, the besieged enclave had seen a further escalation in hostilities, with reports of mounting civilian casualties, as well as widespread damage and destruction to civilian infrastructure due to air- and ground-based strikes.

An additional 133,000 people are now displaced from eastern Ghouta. More than 44,000 of these people are in severely overcrowded IDP sites in rural Damascus, while almost 50,000 others – mostly civilians and some fighters – have been evacuated to Idlib and Aleppo, where the humanitarian response has already been stretched to breaking point.