Turkish media reports a man wounded when a car bomb exploded in the capital Ankara last month died of his injuries Monday, bringing the death toll in the attack to four.

A militant group, the Kurdistan Freedom Falcons, claimed responsibility for the September 22 bombing which wounded at least 15 others. The Freedom Falcons, an offshoot of the Kurdistan Workers Party, or PKK, has threatened more attacks in Turkish cities.

The bomb attack took place near government buildings and a school, damaging cars and shops in the surrounding area. Interior Minister Idris Naim Sahin said the intent was to inflict as much harm as possible, as the blast occurred in an area of heavy car and pedestrian traffic.

Turkey, the European Union and the United States regard the PKK as a terrorist group.

The outlawed PKK has escalated attacks against Turkish targets in recent weeks. Last week, Kurdish rebels attacked multiple police facilities in southeastern Turkey, killing at least five people.

Turkish forces have responded by increasing their airstrikes against suspected rebel bases in northern Iraq. In August, Turkey's military said it killed as many as 160 Kurdish rebels in air and artillery strikes across the border.

Turkish Prime Minister Recep Tayyip Erdogan has said Ankara's “patience is running out” with the rebels, who have waged a campaign for autonomy in the country's largely Kurdish southeast since 1984. The conflict has killed more than 40,000 people.