A senior government official said authorities believe Sunday's attack was carried out by two bombers — one of them a woman — and was the work of Kurdish militants.
The state-run Anadolu Agency says police detained dozens of suspected militants in southern Adana city on Monday.
It was the second deadly attack blamed on Kurdish militants in the capital in the past month and President Recep Tayyip Erdogan vowed to bring "terrorism to its knees."
The blast came as Turkey's security forces were set to launch large-scale operations against militants in two mainly Kurdish towns after authorities imposed curfews, prompting some residents to flee.
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