Turkish warplanes struck Kurdish insurgents for the first time in nearly two years, Turkish media reported Tuesday, in attacks that threatened to further complicate efforts to persuade Ankara to join the U.S.-led coalition fighting the Islamic State.

The bombardment against the Kurdistan Workers’ Party, or PKK, heightened tensions between Turkey’s government and the country’s Kurdish population, which has been angered by Ankara’s refusal to help Kurdish fighters defending the Syrian border town of Kobane against the advances of the Islamic State militant group.

The Turkish airstrikes on PKK targets coincided with a sharp increase in U.S. attacks on the Islamic State in Kobane aimed at helping the Kurdish fighters in the town, who are affiliated with the PKK.

The U.S. Central Command said it carried out 21 strikes in and around Kobane on Tuesday, and it suggested that the attacks are starting to have an impact. Kurdish activists reported that Kurdish fighters recaptured a strategic hill to the west of the town from the jihadists, helped by the cover provided by the U.S. strikes.

“Indications are that airstrikes have slowed ISIL advances,” a U.S. Central Command statement said, using an alternative acronym for the Islamic State. “However, the security situation on the ground there remains fluid, with ISIL attempting to gain territory and Kurdish militia continuing to hold out.”

The gains eased concerns that Kobane is in imminent danger of falling to the militants. But Turkey’s reluctance to do more to help Kobane’s Kurds has provoked a backlash at home, with Kurds staging protests nationwide and PKK leaders threatening to call off a two-year-old peace process if Kobane is lost to the Islamic State.

The PKK, which the United States and Turkey have deemed a terrorist organization, led a nearly 30-year uprising for greater rights in Turkey’s Kurdish-dominated southeast before a cease-fire last year brought hope for an end to the bloodshed. The battle for Kobane has threatened to reignite the war, and PKK fighters have begun returning to Turkey from bases in northern Iraq where they had retrenched after the cease-fire was announced.

Turkish jets struck PKK positions overnight close to the southeastern town of Daglica — near the borders with Iran and Iraq — after Kurdish rebels launched an attack on a military barracks nearby, the Hurriyet Daily News and other Turkish news outlets reported.

The Firat News Agency, which is close to the PKK, said airstrikes hit at least five locations, and it claimed that the Turkish military had shelled PKK bases for three days beforehand.

In an effort to find a solution to the tangle, Iraqi Kurdish leaders hosted a meeting of rival Syrian Kurdish factions in the northern Iraqi region of Kurdistan on Tuesday aimed at reaching a settlement that would ease Turkish concerns about helping Kobane.

The initiative led by Massoud Barzani, the president of Iraqi Kurdistan, sought to persuade the Kurdish Democratic Union (PYD), which oversees the faction fighting in Kobane, to form an alliance with another Syrian Kurdish faction, the Kurdish National Council (KNC), which has close ties to Barzani.

Their dispute goes to the heart of the wider Syrian war, with the PYD aligned, through its affiliation with the PKK, to Syrian President Bashar al-Assad and the KNC allied to the Syrian opposition fighting Assad.

Turkey has said that it will allow support to reach the Kurds in Kobane if the PYD turns against Assad. Barzani, who has good ties with Turkey, has agreed to provide aid as long as the PYD mends fences with the KNC, offering the outlines of a wider settlement to the conundrum.

The priority, said Hoshyar Zebari, a Kurd and former Iraqi foreign minister, is for the factions to set aside their differences, which could prove difficult.

“Our main concern is to get them united now,” he said. “There is an immediate and evident danger of losing everything.”

If there is an agreement, it would open the door to “help and assistance from other sources,” he added.

Turkey has refused to offer military support to the U.S.-led campaign against the Islamic State unless the coalition also targets the Assad regime. The United States has been pressing Turkey to allow American warplanes to launch strikes from the U.S. air base at Incirlik, but Turkey continues to deny the request.

In remarks to lawmakers in Ankara on Tuesday, Turkish Prime Minister Ahmet Davutoglu reiterated that the coalition should extend its fight to the Assad regime.

“Turkey will not embark on an adventure [in Syria] at the insistence of some other countries, unless the international community does what is necessary and introduces an integrated strategy,” he said. “We don’t approve of one-dimensional policies.”

Brian Murphy and William Branigin in Washington contributed to this report.