Turkiye warned on Wednesday that Kurdish infrastructure in Syria was a legitimate target for airstrikes after concluding that two militants who carried out a suicide bomb attack in Ankara came from Syria. The warning is a veiled threat to the US, which supports the Syrian Democratic Forces — the de facto Kurdish army in northeastern Syria. Its main component is the Kurdish People’s Protection Units, the YPG, which Turkiye views as an offshoot of the outlawed Kurdistan Workers Party, the PKK. Two PKK members carried out last Sunday’s attack, the first bombing in the Turkish capital since 2016. Police shot one dead and the other died when his device detonated outside the Interior Ministry, injuring two security officers. “As a result of the work of our security forces, it has become clear that the two terrorists came from Syria and were trained there,” Turkish Foreign Minister Hakan Fidan said on Wednesday. “From now on, all infrastructure, large facilities and energy facilities belonging to the YPG and the PKK in Iraq and Syria are legitimate targets for our security forces. I recommend that third parties stay away from these facilities.” Turkiye conducted air raids against PKK bases in the northern mountains of Iraq hours after Sunday’s attack, and the Defense Ministry published images on Wednesday showing PKK targets being hit in Iraq the night before. Iraqi Defense Minister Thabet Al-Abbasi is expected in Ankara on Thursday for talks with counterpart Yasar Guler amid increased tensions over the Turkish airstrikes. Turkish President Recep Tayyip Erdogan has already launched a series of armed incursions into northern Syria and repeatedly threatened to expand attacks against the YPG. Sunday’s bombing coincided with the opening of a session of the Turkish parliament in which members will be asked to ratify Sweden’s membership of NATO. Turkiye’s ratification has been held up by anger over the refusal by the Swedish police to ban marches by the PKK and their supporters in Stockholm. Some analysts believe the PKK may be trying to block Turkiye’s ratification because it would herald an improvement in Ankara’s ties with Washington. Turkiye has been trying to persuade the US to drop its support for the Syrian Democratic Forces, a policy shift that Ankara may expect in return for its ratification of Sweden’s membership, analysts say.