Beirut: More than a dozen Syrian militants have died in hit-and-run clashes with a US-backed alliance dominated by Kurdish forces in the country´s north, a monitoring group said Tuesday.

The Turkish-backed rebels were locked in a second day of fighting on Tuesday with units from the Syrian Democratic Forces around the village of Ain Daqna.

"Since Monday, 15 fighters from Syrian rebel factions were killed in the clashes and four SDF fighters were wounded, including one in critical condition," the Syrian Observatory for Human Rights monitor said.

Ain Daqna, in Aleppo province, has been held by the US-backed SDF since February.

It lies on a sliver of land contested by the SDF and Turkish-backed rebels.

A local official from the Kurdish People´s Protection Units (YPG) which make up the bulk of the SDF, said his forces had retrieved some of the militants´ bodies.

"We will hand over these nine bodies to the Kurdish Red Crescent in Afrin (west) for their families to retrieve them," Brusk Hasakeh said in a statement distributed to journalists.

Turkish-backed rebels fighting under the banner of "Ahl al-Diyar" said in a statement Monday they had attacked Ain Daqna because they see the SDF as "occupiers."

"We promise our people more flash attacks... We will make them regret occupying this land and displacing thousands," it read.

Syria´s conflict erupted in March 2011 with anti-government protests, but it has since evolved into a complex civil war drawing in regional powers.

Turkey has backed rebels in Syria´s north to take on both the Islamic State group and the YPG.

Ankara considers the YPG a terrorist group and the Syrian branch of the Kurdistan Workers´ Party (PKK), which has waged an insurgency inside Turkey since 1984.

That places it at odds with Washington over the United States´ support for the SDF, which is fighting to oust IS from its Syrian stronghold of Raqa.

Rights groups including Amnesty International have accused the YPG of razing villages and displacing residents in northern Syria, which the militia has denied.