Riot police in Malawi arrested 18 people Thursday after firing tear gas and rubber bullets to disperse illegal street vendors in the capital Lilongwe, police spokesmen said.

Skirmishes and looting broke out when police tried to move vendors who had left designated trading areas and congested the streets, national police spokesman Davie Chingwalu told AFP.

"The vendors were being chased from the streets by police and city authorities to their flea (street) markets, but they resorted to violence, looting shops, stoning vehicles and throwing stones to police officers," he said.

Riot police had to fire tear gas and rubber bullets to disperse the vendors from a busy part of the capital where Asian shops and several markets are located, he said.

Lilongwe police spokesman John Namalenga said 18 vendors were arrested and would be charged with illegal selling, while two others would be charged for conduct likely to cause breach of peace "soon after investigations are over."

Two shops were looted during the mayhem after the shopping area had closed for business.

Three vendors were injured while "fighting for looted goods," said Namalenga.

Malawian street sellers have to trade from designated markets, but many have invaded the streets, causing "congestion and robbery," he added.

Thousands of vendors hawk anything from secondhand clothes to pornography on the impoverished southern African country's streets in a thriving informal sector.

Only about half a million of the 13 million citizens have formal jobs.

Last year the United Nations condemned the police killing of 19 people during a crackdown against anti-government demonstrations in July. More than 275 people were arrested across the country at the time.