Russian jets have bombed the last-remaining Syrian rebel stronghold, threatening a ceasefire reached to prevent a humanitarian disaster.

The raids on Wednesday, which killed at least 13 civilians including six infants, were the first on Idlib since Russia agreed to a de-escalation zone with Turkey in September.

The strikes targeted a displacement camp, as well as a prison - sparking a jail break by dozens of inmates.

Footage of the incidents showed a father cradling his dead son in a hospital, while a man looks dazed with severe wounds to his arm.

Idlib, which is now home to almost four million people, has become the final refuge of those opposed to President Bashar al-Assad’s regime.