The two were accompanying their parties' candidates for Hsinchu County Magistrate in the town of Hsinfeng at around 8:00 p.m. Tuesday when supporters of the different camps began shouting at each other. At least one policeman and several reporters also got caught up in the brawl. Television reports showed Ma being whisked away from the scene in a vehicle.

The DPP blamed police for treating its supporters like criminals. "Police closed me in, allowing me to be beaten with flag poles," Hsieh said.

DPP Chairwoman Tsai Ing-wen also identified the police response as the main cause of the incident. Police were guilty of excessive behavior, maybe under pressure from the president's security detail, Tsai told reporters as her party held its weekly Central Standing Committee in Hsinpu, Hsinchu County yesterday.

The president should pay more attention to the use of state resources during election campaigns and not restrict the freedom of movement of other people, she said.

Police said the ruling Kuomintang had requested permission for its activity, while the DPP had not. Hsieh said the DPP event was merely a walkabout which needed no official permission, while the KMT had prepared a motorcade. Tsai also rejected the police argument, saying she had gone on campaign walks all over Taiwan and had never applied for permission.

Speaking at a news conference at the Legislative Yuan, DPP lawmaker Chen Ting-fei said this was the first time she had heard of police demanding a permit for a simple walkabout. She accused the government of taking the country back to the era of martial law before the late 1980s. DPP lawmaker Kuan Pi-ling demanded the Presidential Office explain the alleged presence of military personnel among KMT supporters.

The KMT struck back by accusing DPP supporters of being the first to provoke the police.

KMT candidate Chiu Ching-chun is facing a strong challenge from a breakaway candidate, County Council Speaker Chang Pi-chin, who enjoys the support of the outgoing magistrate, Cheng Yung-chin. Both were expelled from the KMT for their independent bid. The DPP's Peng Shao-chin, a former lawmaker, comes third in the opinion polls.

Scuffles erupted in Chiayi City Wednesday when DPP mayoral candidate Twu Shiing-jer showed up with supporters outside the campaign headquarters of KMT incumbent Huang Ming-hui to demand a public debate.