At least three people were killed after angry protesters set a government building in eastern Indonesia on fire in protest of the death of a motorcycle taxi driver hit by a police vehicle, according to local media.

"A total of eight people were evacuated by the rescue team after the burning of the Makassar City DPRD Office, three of whom were declared dead, suspected of being trapped inside the room when the fire broke out," local broadcaster Kompas TV quoted Regional Disaster Management Agency acting head Fadli Tahar as saying.

Protesters also torched several vehicles as they hurled rocks and Molotov cocktails, injuring another four people.

Protests

The unrest was triggered after a 21-year-old motorcycle taxi driver, Affan Kurniawan, was killed after being hit by a police armoured vehicle on Thursday.

Affan was reportedly completing a food delivery service order when he was caught in the clash following days of violent demonstrations.

Thousands of motorcycle riders, along with rights activists and politicians, attended his burial on Friday.

Indonesian President Prabowo Subianto on Friday expressed regret over the incident and ordered an investigation into a police officer who fatally struck Affan with an armoured vehicle.

Prabowo said the officers involved must be held accountable, as he was shocked and disappointed by the excessive actions of the officer.

Indonesian police chief General Listyo Sigit Prabowo also issued an apology to the victim's family and the public and said the incident will be thoroughly investigated.