Turkish airstrikes hit Kurdish militant camps in northern Iraq, hours after at least 28 people were killed and as many as 61 injured in a suicide car bomb attack on Wednesday in Turkey's capital Ankara. A convoy of military vehicles that was passing through the administrative heart of the city, which also houses the military headquarters, was targeted.

While the attack has not been claimed by any group yet, a senior security source said initial signs indicated that Kurdish militants from the outlawed Kurdistan Workers Party (PKK) were behind it, Reuters reported. Turkish Prime Minister Ahmet Davutoglu blamed Syria's PKK-linked YPG group. However, co-leader of the party Cemil Bayik was quoted as saying by Firat news agency that he did not know who was responsible for the blast, but that it could be in retaliation to "massacres in Kurdistan", referring to the Kurdish region in parts of Turkey, Syria, Iraq and Iran.

In a separate development, at least six security personnel were killed and one soldier was seriously wounded in another bomb explosion in southeast Turkey, in the primarily Kurdish Diyarbakir province.

Following Wednesday's bombing, Turkish President Recep Tayyip Erdogan cancelled a scheduled visit to Azerbaijan and vowed that the country was more determined than ever to use its right to self-defence. "Our determination to respond in kind to attacks taking place inside and outside our borders is getting stronger with such acts," he said in a statement.

Turkey is part of a United States-led coalition fighting the Islamic State in neighboring Syria and Iraq. It has also been engaged in a battle against Kurdish militia fighters in northern Syria and in its own southeast region, where a two-and-a-half-year ceasefire collapsed last July. The Turkish government blames the Islamic State militant outfit for recent bombings in the country. As many as 11 German tourists were killed in a bombing in Istanbul a month ago, while 102 people died in twin suicide blasts at a peace rally in Ankara in October.