The West Nusa Tenggara Provincial Council office is seen on fire after it was stormed and looted during a demonstration in Mataram on Lombok Island, West Nusa Tenggara. AFP
"The rights to peaceful assembly should be respected and protected. But we cannot deny that there are signs of actions outside the law, even against the law, even leaning towards treason and terrorism," he said in a speech at the presidential palace in the capital Jakarta.
Protests began on Monday over perceived lavish perks for lawmakers and low wages but viral footage of a police tactical van killing a young delivery driver on Thursday has aggravated the unrest.
At least three people were killed after a fire started by protesters at a council building in eastern Indonesia. Thousands protested in Jakarta and in major cities around the country.
The protests are the biggest and most violent of Prabowo's presidency, a key test for the ex-general less than a year into his rule.
He pledged an investigation into the killing of motorcycle gig driver Affan Kurniawan and promised to help his family. Seven officers in the tactical van were detained for further investigation.
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