An anti-violence and crime forum in Lae in the Papua New Guinea province of Morobe on Wednesday turned violent when around 100 youths rioted smashing shop and car windows.
The forum came after a violent episode last week in which one person was killed after rival groups of people from Highlands provinces clashed.
Abby Yadi, a reporter in Lae with the Post Courier newspaper, says the youths, who aere mostly understood to have been from Morobe, had been attending the forum.
He says blame for the growing violence in the town was directed at Highlands people during the forum.
"They are saying that there is too much violence and too much crime and the Morobians are actually blaming outsiders, especially the Highlanders, for causing many of the problems. The youths when they rioted were actually saying that non-Morobians should be thrown out of the province or out of Lae city."
Some of the businesses that suffered damage were owned by Highlanders.
Police have arrested eight of the youths.