Three Turkish soldiers have been killed and one wounded during clashes with Islamic State of Iraq and the Levant (ISIL) fighters in northern Syria, according to Turkey's armed forces.

In a statement on Friday, the Turkish military said one of its tanks was hit by ISIL fighters around 12:20pm local time, near the Syrian town of Tel el-Hawa.

The area is west of Jarablus near the Turkish border, which was taken from ISIL by the Ankara-backed Free Syrian Army at the start of the operation.

READ MORE: First group of refugees returns to Syria's Jarablus

Friday's attack marked the seventh Turkish casualty so far in Turkey's two-pronged, cross-border operation against ISIL and Kurdish-led forces in northern Syria.

Turkey first sent tanks across the border on August 24 as part of the operation dubbed "Euphrates Shield"

Four days later, the Turkish army suffered its first fatality in northern Syria, in a rocket attack blamed on Kurdish militia.

Late on Sept. 6, three more Turkish soldiers were killed and four others were wounded in an ISIL attack on two tanks near the town of al-Rai in northern Syria.

Last week, ISIL fighters were expelled from their last positions along the Turkish-Syrian border, depriving the group of a key crossing point for recruits and supplies.

Turkey wants to establish a safe zone in the 91km area stretching from Jarablus to Azaz to the west and says it will continue with the cross-border operation until "all terrorist elements are eliminated" from the region.

READ MORE: Kurds and refugees behind Turkey's Syria offensive

Turkey's operation, which involves tanks, fighter jets and special forces, is targeting both ISIL but also Syrian Kurdish forces that have been key to driving ISIL fighters out of other parts of the Syrian-Turkish border.

The Kurdish YPG militia is a key partner of the US-led coalition against ISIL, and has recaptured large swaths of territory in Syria from the group.

Yet, Ankara considers the YPG a "terrorist" group and has been alarmed by its expansion along the border, fearing the creation of a contiguous, semi-autonomous Kurdish region in northern Syria.

READ MORE: Turkey and Syrian Kurdish forces 'should stop fighting'

Last month, The US defence secretary has called on Turkey and Kurdish forces in northern Syria to stay focused on fighting ISIL and not to target each other.

Turkey, in response, said it would continue to target the Kurdish militia if it failed to retreat east of the Euphrates River.

Meanwhile, NATO Secretary General Jens Stoltenberg said on Friday that he welcomed Turkey's efforts against ISIL in northern Syria without mentioning its clashes with Kurdish fighters in the same region.

"We welcome Turkey's increasing efforts to fight against Daesh," Stoltenberg told Turkish broadcaster NTV, using an Arabic acronym for ISIL, also known as ISIS.

"Turkey has a right to defend itself," he said. "There have been many terrorist attacks coming from the Syrian side."