HARARE, Zimbabwe -- The Zimbabwean police defied a high court ruling issued at midnight on Sunday ordering the release of a renowned human rights lawyer, Beatrice Mtetwa, and continued to hold her on charges of obstructing justice, a rights group said Monday.
"They have defied that court order, and did not implement what they were told to do," said Kumbirai Mafunda, spokesman for Zimbabwe Lawyers for Human Rights, an organization trying to win Ms. Mtetwa's freedom.
At a news conference in Harare, Zimbabwe Lawyers for Human Rights harshly criticized the police for continuing to detain Ms. Mtetwa despite the court order. "Human rights lawyers will not be intimidated, will not bow," said Precious Chakasikwa, a human rights lawyer and vice chairwoman of the organization. "For every Beatrice Mtetwa that these state agents and institutions put behind bars and attempt to embarrass, humiliate and punish without lawful cause, there are 10 other human rights lawyers waiting to take up the mantle."
Security officials arrested Ms. Mtetwa and three senior officials of the Movement for Democratic Change, Zimbabwe's main opposition political party on Sunday, one day after a largely peaceful referendum on a draft constitution.
Ms. Mtetwa was arrested at the home of Thabani Mpofu, a top adviser to Morgan Tsvangirai, Zimbabwe's prime minister and the leader of the M.D.C., whose house was raided by plainclothes police officers on Sunday morning, witnesses said.
The arrests follow months of harsh crackdowns on opposition politicians and civic groups in Zimbabwe ahead of a presidential election that is expected to be held this year.
"There is a very clear, broad campaign going on," said Frances Lovemore of the Counseling Services Unit, an organization that provides medical and mental health services to victims of political violence. It was one of the first organizations to be singled out last year, and several employees were arrested in November.
"This whole attack on the civil society is part of their campaign to delegitimize all the organizations providing any information to people about human rights abuses," Dr. Lovemore said.
After years of misrule and unrest, Zimbabwe is at a critical juncture. In 2008, Mr. Tsvangirai won the most votes in the presidential election, but refused to take part in a runoff because of violent attacks on his party's supporters. Hundreds of people were killed and injured by the police, the army and allies of President Robert Mugabe's party, ZANU-PF. Mr. Mugabe, who according to state radio traveled to Rome on Monday to attend Tuesday's inauguration of Pope Francis, won the disputed runoff and remained in office.
Regional powers brokered an uneasy power-sharing agreement in which the government would reform the security services, rewrite the Constitution and hold a new presidential election.
But wrangling between the political parties dragged out the Constitution-writing process, and the draft that Zimbabweans voted on Saturday was substantially watered down, critics say, because it failed to check the presidents expansive powers. Still, the new charter was expected to win approval, and early results heavily tilted toward "yes" votes.
The stakes are high in the presidential election. Mr. Mugabe, who has been in power since 1980 and is now 89, failed to win outright in 2008, and many here worry that he will use the country's police and security forces to keep opposition supporters away from the polls to avoid defeat.
"Already the telltale signs are there," said Douglas Mwonzora, the senior M.D.C. official on the constitution-drafting commission. "Unless the international community takes full responsibility and discharges its full duty to ensure the regime of Mugabe is brought into check, we will see a repeat of 2008."
Human rights groups have borne the brunt of the crackdown. This month the police raided the offices of the Zimbabwe Peace Project, a pro-democracy organization, and arrested its director, Jestina Mukoko. Ms. Mukoko was also abducted and tortured by the security services in 2008. In January the leader of ZimRights, another human rights organization, was detained and accused of conducting illegal voter-registration drives. The police have seized two-way and shortwave radios from other organizations, claiming they were broadcasting illegally.
Ms. Mtetwa's arrest on Sunday particularly troubled activists. Though she has been at the forefront in defending human rights groups, some activists said, she has always acted as a lawyer defending her clients, not as an activist herself.
"Her work has been very critical to keeping human rights defenders going in terms of the works they do," said Irene Petras of Zimbabwe Lawyers for Human Rights.
In a recorded statement sneaked out of the Harare police station where Ms. Mtetwa was being held, she said she had been called to Mr. Mpofu's house on Sunday morning by one of his colleagues, who informed her that he had been arrested and that his house was being searched. She demanded that the officers show her a search warrant.
"I asked for a search warrant, they said they would give it to me at the station," Ms. Mtetwa said. "I said, no, you cannot give me a search warrant at the station after you have searched."
The officers tried to take away her cellphone and purse, but Ms. Mtetwa resisted and was placed under arrest.
"The allegation is that I have been obstructing the police in the performance of their duties," she said. "The view I take is they have been obstructing me in my duties as a lawyer. I have a client whose rights have been violated, and I am unable to help him because I am now an accused myself."
This article originally appeared in The New York Times.