A Kurdish militant group, the Kurdistan Freedom Hawks (TAK), reportedly claimed responsibility Friday for a bombing in the Turkish capital that killed 28 people. The group said the bombing, carried out Wednesday in Ankara, was in response to the policies of President Recep Tayyip Erdoğan, and vowed future attacks, Reuters reported Friday.

The group once was linked to the banned Kurdistan Workers Party, also known as the PKK, which has been engaged in a decadeslong war with the Turkish state. In recent months, amid spillover from war in Syria, a tenuous ceasefire has collapsed as parts of Turkey’s southeastern, predominantly Kurdish region have turned into battlefields. The Kurdistan Freedom Hawks reportedly split from the PKK after disagreements over tactics.

The attack Wednesday occurred as military buses waited at an intersection in Ankara’s city center. The country’s parliament, military headquarters and army lodgings sit nearby. In a statement on its website, the Kurdistan Freedom Hawks said the attack was carried out by a 26-year-old Turkish citizen born in Van, an eastern city.

The Kurdistan Freedom Hawks, despite severing its ties with the PKK, has also been labeled a terrorist organization by the U.S. and Turkey. The PKK, as well as other Kurdish militant groups, have fought for greater autonomy for Turkey’s Kurdish minority and recent months have seen those calls grow amid surging violence.

The Kurdistan Freedom Hawks has in the past targeted tourist areas. In December, members of the group carried out an attack at Istanbul’s Sabiha Gokcen airport, damaging five aircrafts and leaving one person dead.

Turkish officials, who are concerned Kurdish rebels in Syria have emboldened militants at home, said early on that the People’s Protection Units (YPG) — a Syria-based Kurdish group — was responsible. The group, supported by the U.S. in the support against the Islamic State group, also known as ISIS, rejected any involvement in the attack.