BEIRUT – Air strikes have hit a hospital in a rebel-held area of Syria’s Aleppo, killing 20 people, including three children and the last paediatrician in the city, the Syrian Observatory for Human Rights says.

The Britain-based war monitor said two other doctors were also among those killed. In a statement on its Facebook page, the Civil Defence rescue service in rebel-held areas of Aleppo put the death toll at 30.

The Observatory also stated that in the past six days in Aleppo, 84 civilians had been killed in government air strikes and 49 civilians were killed in rebel shelling of government-held areas.

Syria has barely been holding onto a fragile cessation of hostilities this year, with experts expressing cautious optimism about its prospects.

The United Nations special envoy to Syria urged the United States and Russia to help revive peace talks.

“In the last 48 hours, we have had an average of one Syrian killed every 25 minutes, one Syrian wounded every 13 minutes,” Staffan de Mistura said Thursday.

He said the truce is barely holding and “hangs by a thread.”

– with other agencies