ANKARA: Turkey has deployed additional troops and equipment along part of its border with Syria as fighting north of the city of Aleppo intensifies, security sources said, but Prime Minister Ahmet Davutoglu said there were no immediate plans for any incursion.

Ankara has mooted the creation of a “secure zone” on Syrian territory due to concerns about Syrian Kurd advances and the presence of ISIS militants, as well as the possibility of a fresh wave of refugees fleeing conflict.

Security sources and officials in the capital Ankara said the Turkish army had stepped up security, also sending in special forces, due to the heavy fighting.

Syrian government forces mounted heavy airstrikes Friday against rebel positions in and around Aleppo, the focus of an insurgent offensive aimed at capturing areas controlled by President Bashar Assad.

“It’s correct that we have taken precautions to protect our border. If there’s any circumstance across the border that threatens Turkish security, orders to act have been given,” Davutoglu told broadcaster Kanal 7.

“[But] no one should have the expectation that Turkey will enter Syria tomorrow or in the near term,” he said. Some media had speculated that a cross-border operation was imminent. “It’s wrong to expect that Turkey would undertake such a unilateral intervention in the immediate term if there is no such risk,” Davutoglu said.

A senior Turkish official said Ankara was uncomfortable both with the presence of hard-line ISIS militants there and the prospect of Kurdish forces controlling the whole border.

He told Reuters Turkey’s link to Aleppo was of critical importance and Ankara would act if Kurdish forces took control of Jarablus, a Syrian town just west of the Euphrates River across the border from Turkey’s Karkamis. “Currently many soldiers have been sent to the border region. This shows Turkey’s decisiveness. But these are definitely not preparations to cross the border,” he said, adding there was no plan to enter Syria unilaterally.

Jarablus, its low-rise concrete buildings visible from Turkey, appeared quiet Friday and there were no immediate signs of significant activity at a military outpost on the Turkish side of the border, a Reuters witness said.

Ankara sees the widening Kurdish presence as a threat, viewing the YPG forces at the border as an offshoot of the PKK militant group which has fought Turkey since 1984 in a conflict which has killed more than 40,000 people.

Foreign Ministry spokesman Tanju Bilgic said there was concern about a new wave of migrants heading to Turkey, which is already sheltering more than 1.8 million Syrian refugees. “There are 4-4.5 million people living there. It’s important for us that these people are not pushed north to our border, it’s important that ISIS and the [Assad] regime are prevented from [attacking] that region,” he told reporters.

“This clearly demonstrates why we want a safe zone and a no-fly zone ... with the aim of creating a secure region for these people so that they can still live within Syria,” he said, adding that option was still under discussion with Washington.

U.S. Ambassador to Ankara John Bass said Thursday that Turkey and the United States were working together to address the threat posed by ISIS fighters in northern Syria. But the U.S. State Department said it had no “solid evidence” Turkey was considering a buffer zone in Syria.

Intense fighting, including explosions, could be heard from the Turkish border town of Kilis late Thursday, just to the north of the Syrian city of Azaz, witnesses said. They said the situation was quiet Friday morning.

The security sources said the Azaz fighting was between ISIS militants and a joint force of Al-Qaeda’s Syrian offshoot the Nusra Front and Western-backed rebels, who have been clashing in the north Aleppo countryside for weeks. The Syrian army and allied militias hold western districts of Aleppo.

Davutoglu said Assad had been cooperating with ISIS militants in attacking the moderate opposition. Syrian officials have dismissed such allegations in the past, pointing to their own battle against ISIS.

Davutoglu said if Aleppo were cut off by fighting it could result in a massive new influx of people into Turkey.