The International Committee of the Red Cross is postponing its relief work to reassess its security detail, after a deadly attack on its staff.

A UK-based monitor said 12 Red Crescent volunteers and drivers were killed in an airstike late on Monday whilst delivering humanitarian aid to western Aleppo province. It came hours after the Syrian military declared an end to a week-long ceasefire.

The Syrian Observatory for Human Rights also said the attacks were carried out by either Syrian or Russian aircraft, adding that there had been 35 strikes in and around Aleppo city since the truce ended.