Kurdish fighters in northern Syria have accused the Turkish military of attacking their positions near a border town at the weekend.
There was no immediate confirmation from Turkey, where an official said the government was investigating the claims.
"The Turkish army targeted yesterday (Saturday), and the morning of October 25, positions held by our units along the border with Tal Abyad," the Kurdish People's Protection Units (YPG) said in a statement dated Sunday.
In June, the Kurdish fighters and their Arab rebel allies expelled Islamic State group (ISIS) jihadists from Tal Abyad after fierce clashes.
The allegations of Turkish attacks come amid heightened tensions as Turkey wages a relentless military campaign against Kurdish militants both at home and in northern Iraq.
Turkey considers the YPG an offshoot of the Kurdistan Workers' Party (PKK), which has waged a bloody insurgency in the southeast of the country since 1984.
President Recep Tayyip Erdogan's spokesman Ibrahim Kalin on Monday accused the Democratic Union Party (PYD) – the political arm of the YPG – of trying to create a "de facto situation" in northern Syria on the pretext of fighting ISIS.
"We will naturally never allow this game," he said on NTV television.
Erdogan on Monday vowed that Turkey would press on with its war against "terrorists" before and after Sunday's election.
"They will continue against all terrorist organisations," he said, adding that Turkey makes no distinction between the PKK, the Islamic State and the DHKP-C, an outlawed Marxist group that has carried out a number of attacks.
A fragile peace process between Ankara and the PKK collapsed after a deadly attack in July on a mainly Kurdish town on the Syrian border blamed on ISIS extremists triggered a wave of tit-for-tat violence between Turkish forces and Kurdish rebels.
Kurdish fighters control large parts of northern Syria on the Turkish border, where they have for months engaged in bitter fighting with ISIS jihadists.
The Kurds in Syria last week said they had incorporated Tal Abyad into their "autonomous administration" in the north of the country.
AFP contributed to this report.