BEIRUT — Turkish airstrikes targeted Kurdish militant strongholds in northern Iraq on Monday, a day after a suicide car bombing in Turkey’s capital killed at least 37 people and raised concerns over expanding violence from an internal war with separatists.
There was still no assertion of responsibility from Sunday’s blast in Ankara — less than a month after a similar attack in the city — but the rapidly organized airstrikes suggest Turkish officials suspect Kurdish separatists, who wage attacks in Turkey but have bases over the border in northern Iraq.
Turkey’s Kurdish militant, led by a group known as the Kurdistan Workers’ Party, or PKK, have battled for greater autonomy in southeast Turkey for decades. But unrest has escalated recently on yet another front in a region already in deep turmoil over the Syrian civil war and the Western-led campaign against the Islamic State.
At the same time, Turkey also has bombed sites of another Kurdish group based in Syria, claiming the U.S.-backed fighters seek to make territorial gains as part of their fight against the Islamic State.
Prime Minister Ahmet Davutoglu, whose office was about 200 yards from Sunday’s blast site, promised “the heaviest punishment” for the bombers.
The Associated Press, citing a senior government official, reported that authorities believe Sunday’s attack was carried out by two assailants — a man and woman — linked to Kurdish militants. The official spoke on condition of anonymity because the investigation is ongoing.
In northern Iraq, warplanes struck at least 18 PKK positions including bases in the Qandil mountains, a base for the group’s leadership, Turkey’s state-run Anadolu Agency reported. Targets included ammunition depots, bunkers and shelters, the agency said.
Sunday’s blast, in a busy area of Ankara, occurred less than a mile from a car bombing Feb. 17, which targeted a bus full of Turkish soldiers, killing 28 of them. An offshoot of the PKK claimed responsibility.
Smaller-scale attacks have been commonplace against Turkish military targets in the largely Kurdish southeast since a cease-fire broke down last summer. The two recent attacks, however, suggest that the militants are seeking to escalate the fight by taking it into the heart of the country and hitting civilians as well.
The U.S. Embassy warned Friday in a message to American citizens that a terrorist attack might be imminent in Ankara, but it did not identify any group. A State Department statement condemned the latest bloodshed, saying that the United States remains committed to “combating the shared threat of terrorism” with NATO-ally Turkey.
The Islamic State has also carried out attacks in Turkey in recent months. The worst killed more than 100 people in Ankara at a Kurdish peace rally in October. In Istanbul, 12 people, most of them German tourists, died from injuries after a suicide bomber in January struck the historic Sultanahmet district.
The U.S government, like Turkey, has designated the PKK a terrorist organization. But Washington has refused Turkey’s demands to add the Syrian Kurds to the list, saying it regards the group as a vital ally in the fight against the Islamic State.
Murphy reported from Washington.