GENEVA - Swiss police fired tear gas and rubber bullets on Saturday at hooded protesters who broke windows and set cars alight during a demonstration ahead of a major WTO conference in Geneva.

Thousands marched in the protest ahead of the World Trade Organization ministerial meeting beginning on Monday, with the vast majority of demonstrators not participating in the violence.

Organizers later decided to end the demonstration due to the violence and because police prevented the march from continuing to WTO headquarters, the Swiss ATS news agency reported.

Some 200 violent protesters infiltrated the march and "began to inflict damage right from the start of the demonstration," police spokesman Patrick Puhl said. Police fired tear gas and rubber bullets to stop them.

Officers had moved in after protesters broke windows at a jewellers, banks and a hotel. Vehicles parked along the march route, particularly luxury cars, were damaged, with at least four set alight, Puhl said.

One young protester dressed as a vampire told AFP he "understood people's anger as the crisis had hit them very hard" while an elderly woman said that the recent economic turmoil gave people "plenty to be angry about."

Organizers put the total number of protesters at 5,000, while police said it was 3,000.
Police spokesman Eric Grandjean told AFP that 33 demonstrators had been arrested, including 14 Black Block members for their involvement in the riots and four others for looting items from local stores.

Next week's gathering falls on the 10th anniversary of the ministerial meeting in Seattle, which was marked by violent street protests.

More than a hundred ministers will gather for the WTO conference, though there have been concerns linked to the United States and European Union.