Assad allies bomb Turkish-backed FSA amid warnings on Aleppo advance

Forces allied to President Bashar al-Assad in Syria warned Turkey on Wednesday against any advance towards their positions to the north and east of Aleppo, as Turkish officials accused the Syrian government of carrying out a strike on its allies.

It was the first time a direct clash between Syrian forces and the Turkish-backed rebels has been announced. Two rebels were killed and five wounded, the Turkish army said.

The Turkish military said a helicopter "assessed to belong to regime forces" bombed the rebels in a village near Akhtarin, a town 5km southeast of Dabiq, late on Tuesday.

Dabiq is a former Islamic State stronghold which the rebels seized from the militants this month.

"This kind of attack will not stop our fight against Daesh (Islamic State)," said Turkey's foreign minister, Mevlut Cavusoglu. "This operation will continue until al-Bab. The operation needs to continue, and it will."

The reported attack came as pro-Assad forces warned that any attempt by Turkish-backed forces to advance on Syrian positions would be seen as a breach of "the red lines".

The field commander of the forces allied to Damascus - who was not identified by name, nationality or affiliation - made the comments during a tour of frontlines to the north of Aleppo in a written statement sent to Reuters by an official from the same alliance.

"We will not let anyone use the excuse of fighting Daesh to advance and attempt to draw near to the defences of the allies forces," he said.

The alliance fighting in support of Assad includes the Lebanese group Hezbollah, Iraqi militias, and the Iranian Revolutionary Guards.

On Wednesday, Erdogan emphasised that Turkey's operations in Syria were not intended to stretch to the city of Aleppo.

"Let's make a joint fight against terrorist organisations. But Aleppo belongs to the people of Aleppo, we must explain this ... making calculations over Aleppo would not be right," Erdogan said in a speech in Ankara.

Turkey's incursion into Syria, launched two months ago to drive IS from its border and prevent Kurdish militia fighters from gaining ground in their wake, has complicated an already messy battlefield in northern Syria.

As the Turkish-backed rebels push south towards al-Bab, an IS-held town 35km northeast of Aleppo, they face confrontation with both Kurdish and pro-Assad forces, whose frontlines lie close by.

The Syrian military could not immediately be reached for comment, but it said last week that the presence of Turkish troops on Syrian soil was a "dangerous escalation and flagrant breach of Syria's sovereignty".

It warned it would bring down any Turkish warplanes entering Syrian air space.

Turkey launched "Operation Euphrates Shield" two months ago, sending tanks and warplanes into Syria in support of the largely Turkmen and Arab rebels.

Erdogan has also said the operation will continue to al-Bab, which the Kurdish YPG militia (Popular Protection Units) is also seeking to control.