At least two doctors in Syria's opposition-held northwest have been infected with the coronavirus, a monitoring group reported, the latest confirmed cases in the overcrowded rebel enclave.

The new infections raise the number of confirmed cases to three in the area, where health care facilities have been devastated by years of civil war, and where testing has been limited due to scarce resources.

Observers fear the virus could spread easily in Idlib province, a concern compounded as Russia, an ally of the Syrian government, moved at the UN Security Council to reduce cross-border aid from Turkey. Aid groups and UN agencies say such a reduction would hamper aid delivery of life-saving assistance amid a global pandemic.