At least 35 people were killed in riots last week when members of Turkey's 15-million-strong Kurdish minority rose up in anger at the government for refusing to help defend the Syrian border town of Kobani from an ISIS assault.
U.S. President Barack Obama, who ordered a bombing campaign against ISIS fighters that started in August, was to discuss the strategy on Tuesday with military leaders from 20 countries, including Turkey, Arab states and Western allies.
In particular, U.S. officials have expressed frustration at Turkey's refusal to help them fight against ISIS.Washington has said Turkey has agreed to let it strike from Turkish air base; Ankara says this is still under discussion.
Meanwhile, ISIS fighters have been fighting their way into the mainly Kurdish Syrian border town of Kobani, where the United Nations says thousands could be massacred within full view of Turkish tanks that have done nothing to intervene.
The fate of Kobani could wreck efforts by the Turkish government to end the insurgency by PKK militants, a conflict that killed 40,000 people but largely ended with the start of a peace process in 2012.
The unrest shows the difficulty Turkey has had in designing a Syria policy. Turkey has already taken in some 1.2 million refugees from Syria's three-year unrests, including 200,000 Kurds who fled the area around Kobani in recent weeks.
"PROVOCATIONS COULD BRING MASSACRE"
Jailed PKK co-founder Abdullah Ocalan has said peace talks between his group and the Turkish state could come to an end by Wednesday. After visiting him in jail last week, Ocalan's brother Mehmet quoted him as saying: "We will wait until October 15 ... After that there will be nothing we can do.
There was no immediate comment from the military on the report that it bombed Kurdish positions, once a regular occurrence in southeast Turkey but something that had not taken place for two years.
Prime Minister Ahmet Davutoglu said the Turkish military had retaliated against a PKK attack in the border area, without referring specifically to air strikes.
Hurriyet newspaper said the air strikes caused "major damage" to the PKK. "F-16 and F-4 warplanes which took off from (bases in the southeastern provinces of) Diyarbakir and Malatya rained down bombs on PKK targets after they attacked a military outpost in the Daglica region," Hurriyet said.
The general staff said in a statement it had "opened fired immediately in retaliation in the strongest terms" after PKK attacks in the area, but did not mention air strikes.
"TOO LATE FOR US"
The battle for Kobani has grinded on for nearly a month, with ISIS slowly advancing and now in control of much of the town. Kurdish fighters known as Popular Protection Units (YPG) want Turkey to allow them to bring arms across the border.
"There are fierce clashes, with no retreat or progress (by ISIS). Yesterday, (IS) detonated three suicide car bombs in eastern Kobani," said Ocalan Iso, deputy head of the Kobani defence council.
The U.S.-led coalition has hit Islamic State positions in and around the town but failed to halt the advance. At least six air strikes were heard from the Turkish side of the border on Tuesday. Gunfire and shelling were audible from the Turkish side, where Kurds, many with relatives fighting in Kobani, have maintained a vigil, watching the fighting from hillsides.
Kurdish people attend the funeral of YPG (People's Protection Units) fighters in the town of Suruc, Sanliurfa province, on October 14, 2014.
Kurds complain that hundreds of refugees were detained after crossing into Turkey, and that wounded fighters died at the frontier because Turkish border guards would not let them in.
"If they had received help, even up to one hour before their deaths, they could have lived," said Omar, 34, a Kurdish activist who brought three wounded fighters to the frontier last week and watched them die. "Once the (Turkish) soldiers realized they were dead, they said, 'Now you can cross with the bodies.'
I cannot forget that. It was total chaos, it was a catastrophe. "Kurds in neighboring Iraq, who are also fighting hard against ISIS, said they had sent ammunition to help their Syrian brethren in Kobani.
Syrian Kurds said the shipment could not get to Kobani without Turkey opening a supply route. In Iraq, Kurdish forces and government troops have rolled back some ISIS gains in the north of the country in recent weeks, but the fighters have advanced in the west, seizing territory in the Euphrates valley within striking distance of the capital Baghdad.
The United States used helicopter gunships against the militants last week for the first time to prevent what Washington described as a threat to Baghdad's airport.