The government has accused the outlawed Kurdistan Workers’ Party (PKK), designated as a terror group by Ankara and its Western allies, for last Sunday’s attack.

The victims included two girls aged nine and 15.

The PKK and its Syrian offshoot YPG have denied involvement. No individual or group has claimed responsibility for the attack.

Turkish police captured the chief suspect Alham Albashir — a Syrian woman who is said to have been working for Kurdish militants — in an Istanbul suburb.

Albashir has reportedly confessed to planting the bomb during her interrogation.

The Istanbul court remanded 17 suspects in pre-trial detention on charges of “destroying the state’s unity”, “deliberate killing” and “deliberately attempting to murder”, the Anadolu news agency reported.

Albashir said she joined the PKK because of her boyfriend’s influence and maintained her ties to the group after she broke up with him, the agency said.

The attack was the deadliest in five years and evoked bitter memories from a wave of nationwide bombings from 2015 to 2017 that were blamed mostly on Kurdish militants and Islamic State jihadists.

Turkish media revealed many details about the woman but questions still remain. She reportedly crossed into Turkey illegally from Afrin near the border, which is controlled by Ankara-backed groups.

There have also been questions also how the woman rented her apartment in Istanbul.

Interior Minister Suleyman Soylu said Ankara believed the order for the attack was given from Kobane, controlled by Syrian Kurdish militia forces in northern Syria.