Turkey's President Recep Tayyip Erdogan has pledged to bring terrorism "to its knees" following a suicide bomb blast in the capital Ankara that killed at least 37 people - the third such attack to hit the city in five months.
Officials say that Ankara's Kizilay Square, a bustling transport hub near the Parliament, prime minister's office and foreign embassies, was targeted.
Prime Minister Ahmet Davutoglu, whose office is just 183m from the site, also promised "the heaviest punishment" for those behind the attack on Sunday evening.
Hours after the attack, Turkish warplanes struck Kurdish militants in northern Iraq, hitting 18 targets, said media reports.
A previous attack last month was claimed by Kurdish militants, who said it was revenge for operations by the Turkish military in the south-east of the country, near the border with Iraq and Syria.
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