Tens of thousands of supporters of the governing Nationalist Party marched through the capital on Sunday to back their candidate, Ma Ying-jeou, who is challenging the current mayor of Taipei.

Andy Beatt reports on violent scenes on the campaign trail in Changhua

Similar numbers from the main opposition Democratic Progressive Party (DPP), who support the incumbent, Chen Shui-bian, held a rally on Saturday.

Tension is running high and violent clashes between rival groups have been reported in many areas in the build up to the legislative and mayoral polls.

On Saturday as many as 17 people were injured when fighting broke out between supporters of the DPP and a rival splinter group, the Taiwan Independence Party, in the central district of Changhua.

Violence flared when Taiwan Independence Party candidate Chen Ming-chiu, unfurled banners denouncing the former chairman of the DPP as a partner of the Chinese President Jiang Zemin.

Petrol bombs

Mass rallies are taking place across Taiwan

The Taiwan Independence Party advocates formal independence from mainland China - a divisive issue in Taiwanese politics.

Mr Chen received a blow to the face which later required hospital treatment and Yao Yu-ching, daughter of DPP candidate Yao Chia-wen, was also injured.

Police later found a cache of baseball bats and petrol bombs in the cars of several supporters of the Taiwan Independence Party.

According to Taiwan's Central News Agency, Mr Chen apparently told officers that the bombs were not intended for an attack, but "in case the cars ran out of fuel."

Officials from both parties were quick to condemn the fighting.