At least 40 people were injured Saturday when police clashed with demonstrators in an anti-government strike called by Bangladesh's main opposition party, witnesses said.
Baton-wielding police confronted protesters marking the second general strike in three days in front of the main office of the secular Awami League opposition party, which is seeking to oust the Islamist government.
A former minister, Matia Chowdhury, was badly bruised along with several other protesters in the clashes, witnesses said.
At least 20 other protesters were hurt in running battles outside the party office.
The rest were hurt in clashes in four other areas of Dhaka, they added.
Some 7,000 police armed with teargas and backed by paramilitary units fanned out across Dhaka to keep order during the strike, which forced shops, schools and most private banks and offices in the capital and other big cities to shut.
Saturday is a normal working day in the world's third-biggest Muslim nation.
Most public buses were off the streets as hundreds of protestors massed in different parts of Dhaka, shouting "Strike, strike".
Police said they would not comment on the reported violence until later Saturday.
Witnesses said at least nine vehicles were torched across Dhaka and two vehicles were damaged in south-eastern Chittagong port city.
The strike was called by Awami League leader Sheikh Hasina Wajed to protest what she called the police's "barbaric" behaviour in putting down Thursday's strike, in which witnesses said at least 50 demonstrators were hurt.
A former cabinet minister and another lawmaker were among the injured. Thursday's protest marked the launch of the opposition's stepped-up drive to oust Zia's two-year-old government.
"The actions against my party's leaders and workers were barbaric. The government has become a savage administration," the Daily Star newspaper quoted Sheikh Hasina as saying.
The government denied the party leaders were hurt in the protests, saying they tripped in the chaos.
Strikes called by parties are common in Bangladesh, which is known for its volatile politics. But witnesses said Thursday's clashes were the most violent since Zia's government was swept to power in 2001, ousting Sheikh Hasina.
The two women have a history of deep personal enmity.
Local Government Minister Abdul Mannan Bhuiyan spurned opposition calls for snap elections. Polls are not due until 2006.
"There is no such atmosphere that calls for early elections," he told the Daily Star, adding the opposition was "bent on creating one obstacle after another to undermine the government."
The Awami League called Thursday's strike after issuing an ultimatum to Zia's government a month ago to resign or comply with 15 demands. They included return of money the Awami League alleges government members looted from public funds, crime control and freedom of press guarantees.
Zia, who holds a two-thirds parliamentary majority, has rejected calls to quit or call new elections, vowing to serve out her five-year term.