The London-based human rights group Amnesty International reports Zimbabwe is escalating its repression against human-rights activists.

A new Amnesty International report gives details on what the organization calls a "sustained attack" through intimidation, arbitrary arrest, assault, and torture of human-rights campaigners by the government of President Robert Mugabe.

One of the report's authors, Audrey Gaughran, says the crackdown stems from the deteriorating political situation in Zimbabwe during the past five years.

"Amnesty is very concerned by the sustained campaign that we believe the government is basically waging against human-rights defenders to prevent them exposing human rights violations, to prevent them criticizing the government, to prevent them mobilizing public action on human rights violations, prevent public demonstrations, peaceful public demonstrations calling for change," she noted.

In one case study, the report details repeated arrest, detention and physical abuse against members of a group called Women of Zimbabwe Arise.  It says at least 300 members of the group have been arrested this year alone at various peaceful demonstrations.

Ms. Gaughran says Amnesty International has tried to make its concerns known directly to the Zimbabwe government, but to no avail.

"We have not been successful in getting a meeting with the government of Zimbabwe in recent times, but we continue to pursue meetings with the government.  We certainly write to the government and express our concerns," she added.

The Amnesty International report calls for Zimbabwe to immediately end the harassment of human-rights activists.  It also appeals for an independent investigation into alleged abuses by the police, and prosecution of those responsible.

There has been no public reaction from the Mugabe government, and officials at the Zimbabwe High Commission in London had no comment.