About 200 women are in police custody in the Zimbabwe capital, Harare, after a protest on Tuesday over food prices and human rights violations.
The group regularly tries to stage Valentine's Day protests
The march in Harare on Tuesday followed a similar protest in the second city, Bulawayo, on Monday, where 181 people were detained overnight.
The protests came as inflation hit 613% - the second highest rate in its history and the current world highest.
Zimbabwe's economy has been in sharp decline for more than six years.
'Restore our dignity'
Both marches were organised by the pressure group Women of Zimbabwe Arise (Woza).
Life expectancy 30 years
3m expecting food aid
20% adult HIV prevalence
3,000 Aids deaths each week
500,000 left homeless this year
200,000 lost livelihoods
Inflation has reached 600%
Crisis compounded by drought
Between 192 and 233 women demonstrators were arrested in Harare on Tuesday and remained in custody on Wednesday, Otto Saki of Zimbabwe Lawyers for Human Rights told the BBC News website by phone from Harare.
Several of them were reported to have babies with them as they were arrested.
The precise number was not clear since some women not involved in the protest were arrested at the same time, Mr Saki said.
"When some of the women were arrested and taken to the holding cells, some individuals were arrested on different charges - there was a joint operation that also netted vendors and some women alleged to be engaged in prostitution."
The 181 women arrested in Bulawayo on Monday were released when the attorney general declined to prosecute them, Mr Saki said.
Woza has tried to stage Valentine's Day protests since new security laws came into force in 2002, but its efforts had previously been thwarted by police.
Under the laws, public demonstrations require police clearance and unauthorised gatherings are frequently broken up.
Tuesday's protesters distributed red roses and Valentine's Day cards in central Harare.
"We were marching to say we want more than day-to-day survival," Woza spokeswoman Jenni Williams told AFP news agency.
"To coincide with Valentine's Day we were saying we want roses and the dignity they stand for and bread in the form of affordable food for everyone."
Zimbabwe has suffered severe fuel and food shortages, which the UN says are due to government mismanagement.
However, President Robert Mugabe puts the blame on sanctions brought in by Western nations following his controversial seizure of white-owned farms.
Zimbabwe's highest inflation level was 623%, reached in early 2004.
In 2005 food prices rose almost tenfold and unemployment rose to 80%, causing living standards to plummet.
Aid agencies estimate that 70% of Zimbabwe's 12 million population now survive on one meal or less a day.
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