FILE - Syrians gather at a site of car bomb in the northwestern Syrian city of Idlib, Aug. 2, 2018.
FILE - Syrians gather at a site of car bomb in the northwestern Syrian city of Idlib, Aug. 2, 2018.

A Syrian army offensive in the rebel-held enclave of Idlib would have a "catastrophic" humanitarian impact and cause levels of civilian suffering unprecedented in the seven-year war, aid agencies have warned.

The government has said it aims to recapture the northwestern Idlib region, a refuge for civilians and rebels displaced from other areas of Syria as well as powerful jihadist forces.

"If there is a large-scale military offensive, what we might see in Idlib in terms of death, injury or displacement is something we haven't seen before. The war is far from over," said Joelle Bassoul, spokeswoman for Care International.

"People will be stranded with nowhere to go, with no aid — what other word can we use besides catastrophic," she told Reuters by phone Tuesday from Beirut.

Destroyed buildings are seen, Aug. 12, 2018, follo
FILE - Destroyed buildings are seen Aug. 12, 2018, following an explosion at an arms depot in a residential area in Syria's northern Idlib province city of Sarmada.

Her comments came a day after the World Health Organization (WHO) warned of rising rates of acute malnutrition in Idlib and said a failure to vaccinate could lead to outbreaks of disease such as polio.

"The health situation in northwest Syria is already dire and looks set to deteriorate," said WHO Regional Emergencies Director Michel Thieren in a statement on Monday as the organization appealed for more funds.

"If WHO does not receive additional funding, more than two million people caught in the cross-fire may have no access to essential health care services, including life-saving trauma care."

Bassoul said health care facilities in Idlib were already overstretched and would be unable to cope with a large military offensive.

Northwestern Syria, where Idlib is located, is the last big area still in the hands of fighters seeking to overthrow President Bashar al-Assad, after the government recaptured the area around Damascus and the southwest earlier this year.

The Syrian army dropped leaflets over Idlib earlier this month, urging people to agree to a return of state rule and telling them the war was nearing its end.

Many live in overcrowded tents and shelters with little access to clean water, food and proper health care, according to aid agencies.

The war has already killed hundreds of thousands of people and driven 11 million from their homes, and the United Nations has expressed worries that an offensive in Idlib could force 2.5 million people toward the Turkish border.

"There are no homes or other forms of shelter left really, even tents," Amany Qaddour, regional director of the humanitarian organization Syria Relief and Development, said in a statement. "Many are prepared to stay [in Idlib] as they have no other options at this point."