Turkey troops mass on Syria border amid Kurdish tensions

Turkey has massed troops on the Syrian border, as clashes with Kurdish militias broke out on Tuesday night sparking fears of wider skirmishes between the two groups.

Turkish artillery fired targeted the People's Protection Units (YPG) in Syria after Kurdish fighters fired on Ankara-backed Syrian forces. 

Ankara said that Free Syrian Army fighters were fired on by the YPG in the northern Syrian town of Azaz, sparking retaliatory shelling from Turkish artillery.

"Fire support vehicles in the region were used to retaliate in kind against the harassing fire and the identified targets were destroyed/neutralised," a Turkish military statement said.

North-west Syria has become a flashpoint for Turkish-backed forces and the YPG, as the two groups battle the Islamic State group and vow for territory.

The Ankara-backed Euphrates Shield force launched operations against IS last year, taking territory in northern Syria as Kurdish forces also competed to carve out territory close to the Turkish border.

It put the two groups on a collision course, with all-out war only averted after the US intervened to back its Kurdish-Arab allies.

Ankara believes the YPG are the Syrian front of the Kurdistan Workers Party (PKK) which has waged a decades' long war against Turkish armed forces costing tens of thousands of lives.

It has also worsened relations between the US and Turkey, with Anakara blaming its NATO ally for arming and backing the Syrian-Kurdish militia.

The US has provided weapons to the Syrian Democratic Forces - which the YPG is a part of - and given air support as the militants battle IS in Raqqa.

The latest incident started as YPG forces fired on FSA units on Tuesday night with heavy machine guns.

Last month, fierce clashes broke out between Turkish-backed Syrian rebels and Kurdish fighters in Aleppo province.