Turkey plans to pursue targets in northern Syria after it completes a cross-border operation against outlawed Kurdistan Workers Party (PKK) militants in Iraq, a senior official said on Tuesday, after a deadly weekend bomb in Istanbul.
The government has blamed Kurdish militants for the blast on Istanbul's Istiklal Avenue on Sunday that killed six people and injured more than 80.
Threats posed by Kurdish militants or Islamic State on Turkey are unacceptable, the official told Reuters, adding that Ankara will clear threats along its southern border "one way or another."
"Syria is a national security problem for Turkey. There is work being done on this already," the official said, declining to be named as they were not authorized to speak to the media.
"There is an ongoing operation against the PKK in Iraq. There are certain targets in Syria after that is completed."
There was no immediate comment from Turkey's foreign ministry.
No group has claimed responsibility for the blast on the busy pedestrian avenue, and the PKK and Kurdish-led Syrian Democratic Forces (SDF) have denied involvement.
Police have detained 50 people as part of the investigation into the blast, Justice Minister Bekir Bozdag was quoted as saying by state-owned Anadolu Agency on Tuesday.
The suspected bomber, a Syrian woman named Ahlam Albashir, was detained early on Monday at a house raid in Istanbul.
Footage showed her with make-up and nail polish on as she was taken from the house wearing a purple jumper with the words "New York" on it. Her shoulders were raised and her face was bruised in a photo shared by police.
Separately, Health Minister Fahrettin Koca said 58 of those injured had been discharged after being treated, while 17 were still in hospital, with six more in intensive care.
Turkey has conducted three incursions so far into northern Syria against the Syrian Kurdish YPG militia, which it says is a wing of the PKK. President Tayyip Erdogan has previously said that Turkey could conduct another operation against the YPG.
While the PKK is deemed a terrorist group by Turkey, the United States and the European Union, Washington allied with the YPG against Islamic State in the conflict in Syria.
Turks are concerned that more attacks could occur ahead of elections set for June 2023, which polls suggest Erdogan could lose after two decades in power. A wave of bombings and other attacks began nationwide when a ceasefire between Ankara and the PKK broke down in mid-2015, ahead of elections that year.