Opposition groups in Zimbabwe have hailed the success of what they are calling the most widely-supported nationwide strike against President Robert Mugabe for years.
The police have vowed to deal ruthlessly with any trouble-makers
The opposition said that most factories and shops in the capital, Harare, and other cities remained closed on the first day of strike, as thousands of people stayed away from work.
The police described the strike - which the authorities said was illegal - as a total failure, saying that more than 60 arrests were made after clashes with protesters.
The BBC's Lewis Machipisa in Harare said that the army was deployed following some violence in the Harare suburb of Epworth.
Violence was also reportered by the BBC correspondent in the second city of Bulawayo.
The strike was called by the Movement for Democratic Change (MDC), whose leader Morgan Tsvangirai has been accused by some party activists of not doing enough to make life difficult for Mr Mugabe since his controversial re-election a year ago.
MDC spokesman Paul Themba Nyathi said that two opposition MPs were among those arrested.
Our correspondent says he saw a bus and a bread van set on fire, while youths threw stones at any cars which were on the streets.
People are sick and tired of this regime and this is their message
Police fired tear gas to disperse protesters from a bus station in the eastern suburb of Mabvuku, according to the Associated Press news agency.
However, some government offices and banks remained open, reported Reuters news agency.
The BBC's Themba Nkosi in the second city, Bulawayo, said there were running battles between MDC activists and government supporters in the suburb of Mpopoma.
He said that most shops and factories were shut in the afternoon after being open in the morning. There was a heavy police presence on the streets.
The authorities declared the strike illegal under tough new security laws and said they would deal strongly with any trouble-makers.
"The police will meet them head-on. We will be very ruthless with them, but within the limits of the law," police Inspector Andrew Phiri told state television.
The MDC has called on people to stay at home on Tuesday and Wednesday and not to demonstrate in order to avoid any violence.
"People are sick and tired of this regime and this is their message," Mr Nyathi said, adding that about 80% of the businesses were affected by the strike.
Queues have become a way of life in Zimbabwe
The strike is being supported by the unions and other civic groups.
Zimbabwe is hit by shortages of everything from food and fuel to cotton wool.
Inflation is running at more than 200% and many factories have closed down, leading to massive unemployment.
Half of the population, some seven million people need food aid.
Mr Mugabe blames the problems on sabotage by foreign enemies opposed to his land reform programme.