The commander of the US-backed Kurdish-dominated Syrian Democratic Forces (SDF) on October 4 accused Turkey of “looking for pretexts to legitimise its ongoing attacks on our region [in Syria] and to launch a new military aggression".  

Mazloum Abdi in posts on social media denied that two men that Turkey says on October 1 committed a terrorist attack outside the interior ministry in Ankara "passed through our region".

Abdi added: "The threat to target the region's infrastructure, economic resources, and populated cities is a war crime, the thing we have witnessed before."

A branch of the Kurdistan Workers' Party (PKK), proscribed as a terrorist group by Turkey, claimed responsibility for what was the first bombing to hit Ankara since 2016.

"It has become clear that the two terrorists came from Syria and were trained there," Turkish Foreign Minister Hakan Fidan, Turkey’s spymaster until he was appointed top diplomat in June, said in televised comments on October 4.

"From now on, all infrastructure, large facilities and energy facilities belonging to [armed Kurdish groups] in Iraq and Syria are legitimate targets for our security forces," Fidan added. "I recommend that third parties stay away from these facilities."

For the US, the SDF was instrumental in the gruelling battle that drove Islamic State fighters from the last parts of Syrian territory that they occupied in 2019. However, the Kurdish People's Protection Units (YPG) make up most of the SDF and Turkey thus views the SDF as an offshoot of the PKK. Given Washington’s alliance with the SDF, an irritant for Ankara is the 900 US special operations forces stationed in the Kurdish-run autonomous region in northern Syria.

Turkey launched air raids against PKK rear bases in the northern mountains of Iraq hours after the attack in the government district of the Turkish capital, in which one assailant perished in an apparent suicide blast and the other was shot dead by security forces on the same day that Turkey’s parliament was being reopened following the summer break.

Turkey’s defence ministry on October 5 said further cross-border raids had "neutralised a large number of terrorists" in five districts of Iraq.

Amid tensions, Iraqi Defence Minister Thabet al-Abbasi was expected in Ankara on October 6 for talks with Turkish counterpart Yasar Guler.

Fidan's remarks indicate that Turkey could step up drone and artillery strikes beyond those it has routinely staged in both Syria and Iraq for the past decade.

Ankara has military bases in Syria and backs groups fighting both Damascus regime forces and the Kurds in Syria.

As its backlash against the PKK intensified, Turkey on October 3 announced the detention of 67 suspected PKK members in raids across Turkey's predominantly Kurdish southeast.

This year, in declining to ratify Sweden’s bid to join Nato, Turkey has listed objections including Stockholm’s refusal to ban marches by the PKK and their supporters in the Swedish capital. Western powers were during the summer hopeful that Ankara would relent and go ahead with a fast ratification this autumn, but there is now speculation among analysts that Turkey might demand the US break off its ties with the SDF in return for it welcoming Sweden into the Western defence alliance. On the other hand, analysts say, the PKK might be trying to block the path to ratification as it does not want to see closer ties between Ankara and Washington that could leave it exposed in Syria.