Turkish jets carried out their first attacks on Islamic State targets in neighboring Syria overnight, Prime Minister Ahmet Davutoğlu’s office announced early on Friday. Two command centers and a rallying point were said to be hit.

The attacks came hours after Turkey allowed the United States to use its Incirlik Air Base to stage attacks against the radical Islamist group that has proclaimed a caliphate in the Levant.

Turkey previously shied away from fighting the Islamic State — and denied its NATO ally use of the Incirlik base — because the group also does battle with the Syrian regime of President Bashar al-Assad that Turkey opposes.

Western countries had nevertheless long urged Turkey, which has the largest army in the region, to join the campaign. Led by the United States, an alliance of Arab and Western states regularly carries out airstrikes against the Islamist group which controls areas in eastern Syria as well as western Iraq.

Turkey also hesitated because action against the Islamists could benefit their main rivals in the north of Syria: Kurdish fighters who are affiliated with the militant Kurdistan Workers’ Party, or PKK.

Despite reconciliation efforts in recent years, Turkey’s Kurdish insurgency has flared up again.

On Friday, police launched operations against Islamic State sympathizers as well as Kurdish separatists and other “marginal leftist groups.” Davutoğlu told reporters that nearly three hundreds suspects had been detained, including 37 foreigners, and that weapons and explosives were seized.

The PKK has killed four policemen and wounded several more in recent days in what it called retaliation for a bomb attack on Monday when an Islamic State supporter killed 32 activists and aid workers in Suruç, a mainly Kurdish town close to the Syrian border.

On Thursday, Turkish troops stationed on the border came under rocket and machine gun fire from Islamic State positions. One soldier was killed.

Islamic State forces control the territory north of Aleppo — Syria’s most populous city before the revolt against Assad started in 2011 — dividing the Kurdish-controlled areas in two. The Kurds want to push the Islamists south so they can link up their various territories which border on Turkey.

The Turks see the ambitions of Syria’s Kurds as a threat, fearing they might inspire the country’s own sizable Kurdish minority to push for independence.

President Recep Tayyip Erdoğan said last month Turkey would “never allow” an independent Kurdistan to be declared on its frontier. “We will continue our fight in that respect whatever the cost may be,” he vowed.

But military action against the Kurds in Syria carries significant risks.

It would dismay Iraq’s Kurdistan Regional Government which enjoys a high degree of autonomy from Baghdad and trades oil with the Turks. And it would unnerve Turkey’s NATO allies who see the Kurds as a bulwark against the fanatical Islamic State.