Updated

Syrian Kurdish forces fighting the Islamic State group near the border with Turkey on Tuesday welcomed airstrikes carried out by the United States and five Arab countries against the militants, while more refugees poured into Turkey from Syria to escape the fierce fighting in the region.

Nawaf Khalil, a spokesman for Syria's Kurdish Democratic Union Party, said airstrikes targeting the Islamic militants are welcome and that attacks on their positions in the Iraq and Syria would help his party's armed wing, which is trying to drive the Islamic State group out of the Kurdish areas in northern Syria.

Meanwhile, an official from Turkey's crisis management agency told The Associated Press that the number of refugees flooding into Turkey since Thursday to escape the Islamic State group's advance had reached 150,000. The official spoke on condition of anonymity because he was not authorized to make a statement on behalf of the agency.

The al-Qaida breakaway group, which has seized territory straddling the Syria-Iraq border, has in recent days advanced into Kurdish regions of Syria that border Turkey. Fleeing refugees have reported atrocities, including stonings, beheadings and the burning of homes.

The U.N. refugee agency, UNHCR, said it was making preparations for hundreds of thousands of people who might cross the border.

"The population along the border was at least 400,000 people," Melissa Fleming, a spokeswoman for the U.N. refugee agency, told the AP. "The Turkish government and UNHCR have braced for the contingency that hundreds of thousands will flee over the border, but we cannot predict any number. It depends on the dynamics of the conflict. But it's better to be prepared."

Khalil, the Syrian Kurdish party's spokesman, said many Syrian Kurdish men were bringing their families into Turkey for safety before returning to Syria to fight the Islamic militants, often climbing up barbed fences.

Meanwhile, Abdullah Ocalan, the imprisoned leader of a Kurdish rebel group fighting Turkey for autonomy has called for a mass mobilization of all Kurds against the Islamic State group.

Ocalan, who is serving a life sentence on a prison island near Istanbul, leads the Kurdistan Workers' Party, which has long fought Turkey for autonomy and is affiliated with Syria's Kurdish Democratic Union Party.

The call could raise tensions at the border where Kurds have clashed with Turkish security forces. Near the frontier, hundreds of Kurds from Turkey have fought with Turkish police firing tear gas and water cannons. The Kurds say Turkey is hampering their efforts to enter Syria and help their brethren.

The area around Turkey's border town of Suruc was heavily militarized on Tuesday with armored vehicles.

__

Suzan Fraser in Ankara, Turkey and Diaa Hadid in Beirut contributed.