TURKISH war planes have launched air strikes on Kurdish fighters in northern Syria in a move likely to raise tensions with the US and risk opening a new battle front.

Turkey wants to oust the YPG militia, which it calls a terrorist group, from Afrin region on its southern border. The YPG has been a key part of the US-backed alliance battling Islamic State.

Russia has moved its troops away from the area, saying it is concerned but will not interfere. Syria denounced Turkey's "aggression" and "brutal attack".

Turkey had been shelling the area for two days, ahead of its declaration of a military operation yesterday. The Turkish army announced that a new air and ground campaign, inappropriately dubbed Olive Branch, had launched at 14:00 GMT, targeting the Kurdish peshmerga militia. Ground forces are expected to to join the offensive today

The operation, it was claimed, would be carried out "with respect for Syria's territorial integrity". A later statement said 108 targets belonging to Kurdish militants had been hit.

Pro-Turkey rebels, known as the Free Syrian Army, also began moving into the area, according to the state-run Anadolu news agency.

The Syrian regime warned it would be seen as a violation of Syria's sovereignty. An estimated half a million people have been killed in the Syrian war. With this new front, the danger is that number will rise again.