A female suicide car bomber who murdered at least 35 people in Ankara had links to Syrian Kurdish rebels, Turkey’s interior ministry said in a statement on Tuesday.

The ministry, which identified the bomber as Seher Cagla Demir, born in 1992, said she had been affiliated with the outlawed Kurdistan Workers’ Party (PKK) since 2013 and then “crossed into Syria and received terror training in the YPG terrorist organization.”

The People’s Protection Units or YPG is a Syrian Kurdish militia that Ankara regards as a terror outfit with links to the PKK.

Nobody has claimed the attack yet that struck the heart of the capital but the Turkish government said “almost certain” evidence pointed to Kurdish rebels. Turkey has been cracking down on Kurdish groups for the past several months.

The interior ministry said a thorough investigation was under way and offered condolences to relatives of civilians who lost their lives in the attack carried out by the “separatist terrorist organization.”

Sunday’s bombing is the second major blast in Ankara in less than a month.

In February, a car bombing targeted military personnel in a nearby area of Ankara, killing 29 people. That was claimed by the Kurdistan Freedom Falcons (TAK), which has ties to the PKK, in revenge for Turkish military operations in the southeast.

The government described that attack as a joint operation of the PKK in cooperation with the YPG.

AFP contributed to this report.