With presidential elections in Zimbabwe less than two months away, opposition leaders say violence is increasing.

At least 15 political activists have been killed in Zimbabwe this year. Most of the victims have been members of the opposition Movement for Democratic Change.

Opposition party officials say one of the worst areas of violence has been the region of Zaka, 250 kilometers south of Harare. Seven Movement for Democratic Change (MDC) supporters have been killed in the past three weeks in Zaka, and another 20 opposition supporters have been kidnapped and have not been seen since.

Independent newspaper reports say violence has become so bad in the Zaka region that a dawn-to-dusk military curfew has been imposed. Residents of the area say they have been told they will be shot dead if they go out of their houses.

The army has made no comment.

Meanwhile, an affiliate of Amnesty International in Zimbabwe, Amani Trust, says it has been unable to learn the whereabouts of more than 300 people who have been kidnapped in the past year.

Amani Trust blames the ruling ZANU-PF party for almost all the kidnappings and speculates many of the victims may have gone into hiding after being tortured and released. Ruling party officials have not commented on the report by the human-rights group.

In another incident, the MDC says the body of one of its supporters who had been listed as missing has been found on a farm owned by Minister of State Security Nicholas Goche. The activist, 59-year-old Moffat Chiwaura, was last seen at the funeral of another MDC supporter who had been killed. The funeral ceremony came to a halt after it was raided by ruling party supporters.

The police have not confirmed Mr. Chiwaura's death.