Turkey has sent new military reinforcements including troops, vehicles and equipment into northern Syria, a war monitoring group and rebel and Kurdish sources said on Wednesday.

The British-based Syrian Observatory for Human Rights said the forces had crossed the border in the last 24 hours and headed toward areas south of Azaz town, which is held by Turkish-backed Syrian rebels.

To Azaz's south are areas controlled by the Kurdish YPG militia, which Turkey has fought in northern Syria.