Turkey on Saturday sent six more tanks into Syria as pro-Ankara forces pressed on with de-mining work in the Syrian town of Jarablus captured from ISIS this week, as a group allied to the Syrian Democratic Forces (SDF) claimed that Turkish warplanes struck civilian homes and positions held by it.

The Turkish military on Wednesday launched an operation codenamed “Euphrates Shield” inside Syria to oust ISIS from the border region and also counter advances by a Kurdish militia detested by Ankara.

An AFP photographer in the village of Karkamis on the Turkish side of the border watched six Turkish tanks roll over the frontier into Syria on Saturday.

The Hurriyet daily had reported earlier that the Turkish armed forces had 50 tanks and 380 personnel on the ground in Syria after three days of operations.

Turkish troops are supporting an even larger force of hundreds of Syrian rebels.

The photographer said that sporadic explosions were audible on the Turkish side of the border as the rebels carried out de-mining work in Jarablus.

The state-run Anadolu news agency confirmed in a story datelined from Jarablus that the rebels were working to destroy explosives left behind by ISIS.

It said that on Friday alone 20 different sets of explosives had been destroyed.

But the Jarablus Military Council, part of the Kurdish-backed SDF, said the attack on the village of al-Amarna caused civilian casualties and called it “a dangerous escalation that threatens the fate of the region.”

There was no immediate comment from Turkish officials.

A Reuters witness saw unidentified warplanes flying over the border region into Syria from Turkey early on Saturday morning, followed by the sound of explosions.

Turkey’s leadership has made clear that the offensive is also aimed at ensuring that the Kurdish People’s Protection Units (YPG) militia, which has led the fight against ISIS in the area, stay east of the Euphrates River.

Ankara says that the YPG has failed to stick to a promise made by its U.S. allies that the militia would move back east across the Euphrates following the seizure of the town of Manbij from ISIS earlier this month.

On Thursday, Turkey shelled positions of the YPG near Manbij but there have been no reports of further activity against the group since then.

Hurriyet said that the Turkish armed forces had been given an order to “strike immediately” should the YPG be seen to make any move towards Jarablus.

Turkey sees the YPG militia and its Democratic Union Party (PYD) political wing, which have links to Kurdish rebels in Turkey, as “terror groups” bent on carving out an autonomous Kurdish region in Syria.