Syria's government on Sunday condemned Turkey for two days of shelling targeting mainly Kurdish forces in the northern province of Aleppo and urged the United Nations to act, state media said.
It also accused Turkey of allowing gunmen and weaponry to enter Syria from the Bab al-Salama crossing into Aleppo province, where government forces have recently launched a major campaign.
"The foreign ministry strongly condemns the repeated Turkish crimes and attacks against the Syrian people and Syria's territorial integrity," state news agency SANA reported.
The ministry called on the UN Security Council to "put an end to the crimes of the Turkish regime," SANA added.
The ministry statement said that on Saturday 12 pick-up trucks equipped with heavy machine guns and ammunition had crossed into Syria from Turkey via Bab al-Salama.
They "were accompanied by around 100 gunmen, some of them Turkish forces and Turkish mercenaries," SANA quoted the ministry as saying.
The Britain-based Syrian Observatory for Human Rights monitor also reported the arrival of a convoy of fighters from Turkey via Bab al-Salama into Aleppo province on Saturday.
"Around 350 Islamist fighters from the Faylaq al-Sham faction crossed from Turkey and entered the towns of Azaz and Tal Rifaat," said Observatory director Rami Abdel Rahman.
He said the convoy had originated in the town of Atmeh, in neighbouring rebel-held Idlib province, crossing from there into Turkey, before re-entering Syria through Bab al-Salama.
The rebel reinforcements come as an alliance of Kurdish and Arab fighters push towards the rebel-held towns of Azaz and particularly Tal Rifaat, in northern Aleppo province.
The alliance, known as the Syrian Democratic Forces (SDF), has also taken the Minnigh airbase from Islamist rebels, and is now battling them for control of Tal Rifaat.
The advances have angered Turkey, which considers the Kurdish component of the SDF to be a branch of the outlawed Kurdistan Workers Party (PKK), which has waged a decades-long insurgency against the Turkish state.
Washington, which has backed the SDF in fighting against the Islamic State group, has also urged the Kurds and their allies not to "take advantage of a confused situation by seizing new territory."
The SDF advance comes in the wake of a major push by Syrian government forces backed by Russian air power in northern Aleppo province.
That operation has left the rebel-held east of Aleppo city virtually encircled and prompted tens of thousands of civilians to flee northern Aleppo province.
Date created : 2016-02-14