The UN aid chief said Tuesday (June 25th) he had asked Russia to explain how it uses data on the location of Syrian hospitals and clinics following a string of attacks on health facilities, AFP reported.

Mark Lowcock, the under-secretary-general for humanitarian affairs, told the Security Council he was "not sure" hospitals that share co-ordinates of their location under a UN deconfliction system will be protected.

More than 23 hospitals have been hit by strikes since Russia-backed Syrian regime forces launched an offensive in late April in the Idlib region, which is largely controlled by Tahrir al-Sham, according to the UN.

On June 20th, an ambulance transporting an injured woman in southern Idlib was hit, killing the woman and three medical workers.

"I have written to the Russian Federation to request information as to how the details provided through the deconfliction mechanism are used," Lowcock said.

Russia, which backs the Syrian regime in its offensive in the north-west, has firmly denied the bombing campaign has targeted hospitals in the Idlib region.

Moscow maintains the military operation is aimed at driving out "terrorists" from the region, which is covered by a de-escalation agreement reached last year between Russia, Iran and Turkey.