A powerful car bomb explosion has rocked the Turkish capital, Ankara, killing three people and injuring 15 others, at least five seriously.

The bomb exploded Tuesday near government buildings and a secondary school, damaging cars and shops in the surrounding area and starting a fire.

Turkish officials say the blast appears to have been a terrorist attack. 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.

No groups or individuals have claimed responsibility for the blast.

Kurdish rebels are fighting for their autonomy in the region and have escalated their attacks on Turkish targets. Turkish officials are threatening an incursion by ground forces against Kurdish rebel bases operating in northern Iraq.