A boy carries his belongings at a site hit by what activists said was a barrel bomb dropped by forces loyal to Syrian President Bashar al-Assad in Aleppo’s al-Fardous district, Syria, April 2, 2015. Photo: Reuters / Rami Zayat / File.

Nearly 300 civilians have been killed in attacks this year in northwest Syria, 93 percent of them caused by strikes by the Syrian government and its ally Russia, the top United Nations human rights official said on Tuesday.

In a statement expressing “horror at the scale of the humanitarian crisis,” Michelle Bachelet denounced direct hits on or near camps of displaced civilians, as well as on medical and education facilities, including two hospitals on Monday. She has previously said such acts could be war crimes.

Her spokesman Rupert Colville, asked whether Syria and Russia were deliberately targeting civilians and buildings protected under international law, told a Geneva briefing: “The sheer quantity of attacks on hospitals, medical facilities, and schools would suggest they cannot all be accidental.”