In Taiwan, 13 people have been arrested following several hours of clashes between riot police and protesters.
The clashes were the worst since the presidential elections
Violence flared after a mass rally in Taipei calling for an independent probe into the shooting of President Chen Shui-bian on the eve of elections.
Opponents of President Chen say suggested the shooting may have been staged to win him sympathy just before voters went to the polls last month.
President Chen won a narrow victory and will be sworn in again in May.
Calm has returned to the streets in the Taiwanese capital after a night of clashes between protestors and riot police.
Nearly 100 people were injured in Saturday night's events, the worst violence since the hotly-disputed presidential elections three weeks ago.
Police say nearly half of those in custody were found to have previous criminal records.
At a news conference, the police said those involved in the skirmishes had clearly been prepared.
Many had carried fire extinguishers, bottles and catapult slings to hurl rocks at police.
The opposition parties have expressed regret over the incident, saying it was not clear if any of those involved were their supporters.
The opposition has been protesting against alleged election irregularities
Meanwhile, the prominent Taiwanese-American forensic scientist, Henry Lee, who has been helping officials investigate the shooting and wounding of the president, said two shots fired at his vehicle had definitely come from outside.
But he said he was unable to tell if the shooting had been staged.
"In the United States, self-inflicted means that you fire the shot yourself, which I think impossible for himself to fire that shot," he explained.
"But that's the only limited interpretation of a staging or not staging."
The opposition parties say Doctor Lee's work has removed some but not all doubt surrounding the incident.
Theyare pushing for a referendum to establish an independent investigation into the shooting and want to know how many extra military personnel were prevented from voting as a result of the national security alert.
They say if those demands and calls for a judicial recount of the disputed election aren't met, they will hold another mass rally one day before the president's formal inauguration next month.