Turkey blamed the attack on the PKK -- a Kurdish separatist group that Turkey, the United States and the European Union have designated a terror organization, and which Turkey has been battling for decades. It was the second deadly blast on Turkish soil attributed by Ankara to Kurdish groups in two days.

At least 28 people were killed and 61 injured in an explosion targeting military vehicles in central Ankara Wednesday, which Turkish Prime Minister Ahmet Davutoglu said was carried out by a member of the YPG, the Kurdish fighting force in Syria.

Turkish military: Deadly explosion a `terror attack` 02:53

"It has been revealed that a YPG member who infiltrated from Syria with members of the separatist terror organization conducted this attack," Davutoglu said, identifying the man as Syrian-born Saleh Najar.

Turkey responded to the Ankara blast with airstrikes in northern Iraq Wednesday night targeting the PKK, which it says is affiliated with YPG.

The YPG is the 30,000-strong armed wing of the PYD, the main Kurdish political actor in Syria, and receives backing from the U.S. as a key partner in the fight against ISIS.

The Turkish general staff said that a group of 60-70 people, including some of the PKK`s top figures, were targeted Wednesday night in the Haftanin region of northern Iraq, close to Turkish border, according to Anadolu. Northern Iraq is home to the majority of that country`s Kurdish population.

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