Kurdish-backed rebels fought Turkish tanks in northern Syria on Saturday, as Ankara ratcheted up its cross-border offensive by launching airstrikes on Kurdish forces.

A Turkish soldier was killed and three others were wounded in a rocket attack on a tank fired from territory held by the Kurdish YPG militia, Turkish military sources said. The soldier's death is the first reported fatality on the Turkish side since the military began its so-called Euphrates Shield operation in Syria on Wednesday.

Syrian rebels opposed to Ankara's incursion said Turkish forces had targeted forces allied to the YPG and no Kurdish forces were in the area.

The Turkish-backed Nour el-din el-Zinki rebel group said fighters advanced on the village of Youssef Beik that lies southwest of Jarablus - a town they recently seized from ISIS militants - in a bid to wrestle control of the surrounding Kurdish-held territory.

Open gallery view This picture taken from the Turkish Syrian border city of Karkamis on August 24, 2016 shows smoke following air strikes by a Turkish Army jet fighter on the Syrian Turkish border village of Jarabulus. Credit: Bulent Kilic, AFP

The rebel group seized the village from Kurdish-affiliated forces and claimed to have captured two Kurdish fighters.

A spokesperson of the Kurdish militias also said that forces allied with the Kurds were battling Turkish tanks south of Jarablus.

The latest clashes highlight concerns that Turkey's incursion into Syria was likely to raise the potential for an all-out confrontation between Syrian rebel groups and Kurdish forces, which are both American allies.

Earlier on Saturday, Turkish security sources said two F-16 jets bombed a site controlled by the Kurdish YPG militia, which is part of the broader U.S.-backed Syrian Democratic Forces coalition. The sources also said the jets hit six ISIS targets.

Turkey's military didn't specify what the airstrikes hit, saying only that "terror groups" were targeted south of the village of Jarablus, where the clashes later ensued.

Saturday's use of warplanes against what Turkey said was a Kurdish YPG militia target highlights its determination to prevent any Kurdish territorial expansion in north Syria.

Any action against Kurdish forces in Syria puts Turkey at odds with its NATO ally the United States, which backs the SDF and YPG, seeing them as the most reliable and effective ally in the fight against Islamic State in Syria.

It adds complexity to the Syrian conflict that erupted five years ago with an uprising against Syrian President Bashar Assad and has since drawn in regional states and world powers.

'Dangerous escalation'

The Jarablus Military Council, part of the SDF, had said earlier on Saturday that Turkish planes hit the village of al-Amarna south of Jarablus, causing civilian casualties. It called the action "a dangerous escalation".

The Kurdish-led administration that controls parts of northern Syria said Turkish tanks advanced on al-Amarna and clashed with forces of the Jarablus Military Council. But the Kurdish administration said no Kurdish forces were involved.

However, the leader of one Turkey-backed rebel group gave a rival account. He told Reuters the rebels battled the Kurdish YPG around al-Amarna and denied any Turkish tanks took part.

Turkish security forces simply said Turkish-backed forces had extended their control to five villages beyond Jarablus.

A video released by Turkey's military showed the Turkish Red Crescent distributing food and aid to people in Jarablus, with the help of Turkish troops. It also showed what appeared to be Turkish-backed rebels flicking v-for-victory signs in the town.

The newly formed Jarablus Military Council has said it was made up of people from the area with the aim of capturing the town and the surrounding region from Islamic State militants. However, the Turkish-backed rebels seized Jarablus first.

Several militias under the SDF banner pledged support to Jarablus Military Council after it reported the Turkish bombing.

The Northern Sun Battalion, an SDF faction, said in a statement it was heading to "Jarablus fronts" to help the council against "threats made by factions belonging to Turkey".

Tension has mounted in Syria's Aleppo region in the past year between the U.S-backed Kurdish YPG force and its allies on one hand and Turkish-backed rebel groups on the other. The two sides have clashed on several occasions.