Turkey claimed its forces had seized control of the Syrian border town of Ras al Ain town on Saturday, as the country's offensive against a Kurdish militia in the region entered its fourth day.
"As a result of successful operations within the scope of Operation Peace Spring, the town of Ras al-Ain to the east of the Euphrates has been brought under control," the Turkish defence ministry wrote on Twitter.
But Kurdish authorities denied the town had fallen to the Turks, saying fighting was continuing.
"Ras al-Ain is still resisting and clashes are ongoing," said an official of the Kurdish-led Syrian Democratic Forces.
An AFP correspondent in the area said Turkish troops and allied Syrian rebels had entered the town but had yet to capture it.
The Britain-based Syrian Observatory for Human Rights (SOHR) also reported that the town, a major target of the Turkish offensive, had yet to be completely taken.
SOHR said the civilian death toll resulting from Turkey's offensive into northern Syria had now risen to 30.
The Kurdish-led administration in northeastern Syria said that 191,069 people had so far been displaced as a result of Turkish military operations. The United Nations on Friday gave a figure of 100,000.
The United States has ramped up its efforts to persuade Turkey to halt the offensive against the US-backed Kurdish YPG forces, saying Ankara was causing "great harm" to ties and could face sanctions.
Turkey launched its incursion after US President Donald Trump spoke by phone on Sunday with Turkish President Tayyip Erdogan and withdrew US troops who had been fighting alongside Kurdish forces.
There has been fierce international criticism of the assault and concern about its humanitarian consequences. .
Mr Erdogan has dismissed the backlash over the operation and said on Friday evening that Turkey "will not stop it, no matter what anyone says".
Thick plumes of smoke rose around Ras al Ain, one of two Syrian border towns targeted in the offensive, on Saturday as Turkish artillery pounded the area, said a Reuters reporter across the frontier in the Turkish town of Ceylanpinar.
Intense gunfire also resounded from within Ras al Ain while warplanes could be heard flying overhead.
It was quieter at Tel Abyad, the operation's other main target some 120 km (75 miles) to the west, with only occasional shelling heard in the area, another Reuters reporter said.
The Turkish-backed Syrian rebels said earlier they had cut the road which connects Ras al Ain and Tel Abyad and had captured 18 villages since the operation began.
On Friday, the Pentagon said US troops came under artillery fire from Turkish emplacements though none of its soldiers were wounded near the Syrian border town of Kobani, 60 km (37 miles) west of the main area of conflict.
Turkey's Defence Ministry said its forces did not open fire at the US base and took all precautions to prevent any harm to it while it was responding to fire from a nearby area by the Kurdish YPG militia, which Ankara regards as a terrorist group.