Police have charged 67 people following the riots in Dunedin over the weekend as the Undie 500 event came to town.

The mayor of Dunedin wants students involved in weekend riots to be punished without regard for their future careers.

Police ran out of pepper spray against an angry mob of around 600 during more ugly Undie 500 related scenes last night.

More than 600 people pelted officers with bottles, bricks and bicycle parts in North Dunedin last night, with concerns for more trouble tonight.

Having an imaginary friend may enhance academic performance.