BEIRUT — Rebel-held northwest Syria is facing an unprecedented coronavirus surge and aid agencies are calling on the world to help provide humanitarian and medical aid, increase hospital capacity and ensure people are vaccinated.

The surge apparently caused by the more contagious delta variant has overwhelmed hospitals with sick patients and is causing shortages of oxygen, according to local officials. The local rebel-run authority imposed a nighttime curfew as of Tuesday while schools and universities were closed and students are getting distant learning.

The region is home to 4 million people, many of them internally displaced people by Syria’s 10-year conflict.

Dr. Khaula Sawah, president of The International Union of Medical Care and Relief Organizations, or UOSSM, says international aid is urgently needed “to prevent a humanitarian disaster. Millions of lives are at stake.”

The rate of positive test results — an indication of the level of virus spread — is around 55%, according to UOSSM and Christian humanitarian organization, World Vision. Only 1.3% of people are vaccinated, according to World Vision.

Local medical authorities say the number of registered coronavirus cases in the region reached nearly 77,000 while deaths reached 1,357.

“People are dying in Northwest Syria because they cannot access hospitals,” says Johan Mooij, World Vision Syria Response Director said in a statement released Thursday.