The Turkish army started bombing Kurdish camps in northern Iraq overnight, hours after a car bomb attack in the capital Ankara killed at 28 people,Reuters reports.
Dozens were also wounded after the car laden with explosives detonated next to military buses near the armed forces' headquarters.
Six Turkish security force members were also killed on Thursday, as a bomb detonated by remote control hit a military convoy in southeast Turkey, according to Reuters.
According to security sources, the convoy was hit on the highway linking Diyarbakir, the largest city in the mainly Kurdish southeast, to the district of Lice.
Turkey's Prime Minister Ahmet Davutoglu said in a speech on live television on Thursday that the perpetrator of the Ankara attack was a member of the Syria Kurdish YPG militia working with insurgents from the PKK. No one has yet claimed responsibility for the attack.
The leader of the Syrian Kurdish YPG has denied his group was behind the attacks in Turkey, and warned Ankara about a ground action in Syria, the Associated Press reports.
He also announced that Turkey would continue to shell positions of the Syrian Kurdish YPG militia and that senior members of the PKK had been killed in air strikes on their camps in Iraq launched by Turkey late on Wednesday.
Davutoglu said that Turkey expects cooperation from its allies against the YPG and PKK both of which the government considers to be terrorist groups.
"In light of information we have obtained, it has been clearly identified that this attack has been carried out by the members of terrorist organisation inside Turkey together with a YPG member individual who has crossed from Syria," Davutoglu said. He also said nine people had been detained following the attack.
According to Reuters, the Yeni Safak newspaper, which is close to the government, said that the man who detonated the car was a Syrian national who had been registered as a refugee in Turkey and the pro-government Sabah newspaper linked the perpetrator to the PKK.
The Turkish military described the attack as a terrorist act and a senior security source told Reuters that initial signs indicated that Kurdish militants from the PKK were responsible.
After a two-year cease-fire between the Turkish government and the PKK ended last summer,Turkey launched a string of attacks against the PKK, which it views as a terrorist organisation.
Cemil Bayik, who is seen as close to the PKK, was quoted by the Turkish Firat news agency: "We don't know who did this. But it could be an act of retaliation for the massacres in Kurdistan." The Turkish government has been accused by Kurds of killing civilians and militants indiscriminately.
Moscow, whose relationship with Ankara has dramatically deteriorated since the downing by Turkish forces of a Russian jet in November, expressed its condolences to the people of Turkey following the deadly explosion. It said the terrorist act underlined the need for all countries to unite to fight international terrorism.
In Stockholm, an explosion on Wednesday severely damaged part of a building that housed a Turkish cultural association. No one was injured, police said, as everybody had left and the building had been locked up earlier in the evening.