By Nelson Banya HARARE, May 8 (Reuters) - Zimbabwean police on Tuesday broke up a planned march against the arrest of two human rights lawyers, which activists say is part of a widening crackdown on President Robert Mugabe's opponents. A Reuters correspondent saw nearly a dozen riot police dispersing about 50 lawyers who had gathered at the High Court in Harare to protest against the detention of lawyers Alec Muchadehama and Andrew Makoni, who were released on bail after being arrested on Friday. He said the police assaulted some of the lawyers with rubber baton sticks and pushed them away from the court. Law Society president Beatrice Mtetwa said she and three other lawyers were picked up by police, beaten and dumped in a suburb just outside central Harare. "They took us in their truck and beat us before dumping us by the road in Eastlea," Mtetwa said. The Law Society called for the march after Muchadehama and Makoni, part of a team representing opposition Movement for Democratic Change (MDC) leader Morgan Tsvangirai and several other opposition figures, were taken into custody. The government has banned rallies. But the lawyers said they were exempt under the Public Order and Security Act (POSA). "The police have no right, even under POSA, to act this way and stop our gathering because the act exempts professional gatherings by professionals to advance issues relevant to their professions," lawyer Jessie Majome, told Reuters. "In this case we are advancing a cause for our profession, but the police seems to be interested only in the power end of the law. It's a disgrace." Mugabe has been defiant despite accusations of widespread human rights abuses at home and abroad. His government has threatened to react strongly against opposition forces the veteran leader accuses of trying to topple his government on behalf of former colonial master Britain. The government, which has been accused of using tough security laws to stifle dissent, last month launched a crackdown on the MDC, accusing it of a "terrorist campaign" of petrol bombings. The opposition denies the charge. Analysts have predicted the government will step up pressure on all its opponents ahead of general elections next year as Mugabe seeks to tighten his grip on power in the face of mounting pressure at home and abroad. Mugabe, 83, has been in power since white rule ended in 1980 and has been endorsed by his ZANU-PF party to run again for president in the elections, which the opposition says it may boycott.