ISTANBUL: Kurdish militants on Thursday claimed a suicide bombing in Ankara that killed 37 people this week and warned of further attacks.

The Kurdistan Freedom Hawks (TAK), linked to militants who have waged a three-decade insurgency against Turkey, said they carried out Sunday’s bombing and vowed further strikes to avenge military operations in the largely Kurdish southeast.

“We have hundreds of members ready to conduct suicide attacks,” TAK said in a statement on its website, describing Sunday’s bombing as revenge for military operations in the southeast, where hundreds of people including civilians, soldiers, police and militants have been killed since July.

It is the second suicide bombing in a month in the heart of Ankara claimed by TAK, opening a dangerous new phase in Turkey’s war with Kurdish militants as deadly attacks spread to its biggest cities well beyond the southeast.

The government sees the rising violence as directly linked to the war in neighboring Syria, where three Kurdish-controlled regions voted to approve the establishment of a federal system in the north on Thursday.

Ankara fears Kurdish ambitions in Syria are fueling separatism at home. It says Kurdish militants in Turkey have deep ideological and logistical ties with Kurdish groups in Syria and have brought weapons and fighters across the border.

That has complicated international efforts to end the war in Syria and raised tensions with Washington, which has backed Syrian Kurdish militia fighters against Daesh.

TAK said it had been targeting the security forces in Ankara and had not intended to kill members of the public. But it said civilian deaths were “inevitable” in its attacks.

Security officials have said the two perpetrators of the Ankara bombing, a man and a woman, were linked to the outlawed Kurdistan Workers Party (PKK), which launched an armed uprising in southeastern Turkey in 1984 to press for Kurdish autonomy.

TAK, which also claimed a February car bombing in Ankara that killed 29 people, says it split from the PKK but experts who study Kurdish militants say they retain close links.

A senior PKK commander described the previous Ankara attack as payback, saying Turkey could see “thousands” of such bombings for its policies toward Kurds.

In the wake of the bombings, President Tayyip Erdogan has called on Parliament to widen anti-terrorism laws that rights groups say are already too broad. They have been used in recent months to detain academics and journalists.

He also wants the immunity from prosecution lifted for deputies from the pro-Kurdish opposition HDP, parliament’s third-largest party, accusing it of militant links.

Prime Minister Ahmet Davutoglu proposed on Thursday that Parliament should lift immunity for all lawmakers facing criminal investigations.