Ten legislators from prime minister Morgan Tsvangirai's Movement for Democratic Change party were arrested at government buildings in Harare Wednesday.
Tafadzwa Mugabe from Zimbabwe Lawyers for Human Rights said that parliamentarians and a senator from Zimbabwe's majority MDC party were arrested Wednesday.
He said they are accused of "disorderly behavior in a public place."
He said the men were at the finance ministry to inquire about government vehicles. When they asked to see a senior public servant, officials called the police and had them arrested.
He said they are being held at Harare Central Police Station.
Another Harare lawyer, Alex Muchadahama said Wednesday, according to his records a further seven MDC legislators are on remand on various charges.
The arrests are likely to raise tension in the unity government Mr. Tsvangirai formed with his rival, President Robert Mugabe, to end the political crisis.
Mr. Tsvangirai's MDC, which defeated Mugabe's ZANU-PF in last year's parliamentary polls, accuses Mr. Mugabe of plotting to dminish his party's majority by arresting its lawmakers on various charges.
The MDC won 100 seats in the 210-member lower house of parliament against ZANU-PF's 99. A smaller faction of the MDC won 10 seats, and an independent holds the one remaining seat.
Before Wednesday's arrests, several more MDC MPs faced charges that the party described as trumped up, and four have already been convicted of various crimes.
Three were sentenced to more than six months in jail, which automatically disqualifies them from holding their parliamentary seats, according to Zimbabwean law.