Two activists killed in Zimbabwe

More than 500 people attended the memorial service

The main opposition party in Zimbabwe, the Movement for Democratic Change (MDC), says two of its supporters have been killed by followers of the ruling party, Zanu-PF.

The news of more political violence came as some 500 mourners were attending a memorial service for David Stevens - the first white farmer killed during the current occupation of white-owned farms.

This intimidation will continue. The MDC is aware of this burden and sacrifice. It will not deter our campaign.

Morgan Tsvangirai, MDC leader

The priest conducting the memorial service said it was essential for "the soul of the country" that Mr Stevens' killers be brought to justice.

A BBC correspondent in Harare says Mr Stevens was apparently targeted because of his support for the MDC.

Price of change

The opposition says two of its supporters were killed on Monday, one in Harare and another who was beaten to death in Shamva, about 80km (50 miles) northeast of the capital.

The MDC leader, Morgan Tsvangirai - the first opposition leader to pose a real challenge to President Robert Mugabe since independence in 1980 - said political violence was the price of change.

"This intimidation will continue. The MDC is aware of this burden and sacrifice. It will not deter our campaign," he said.

Memorial service

Speaking to the BBC before the memorial service, Mr Stevens' wife, Maria, said her husband had held strong views on democracy.

[David Stevens] was so happy when we had independence and he believed President Mugabe was a very go-ahead statesman. But as we all know, things have changed in the past seven years.

Maria Stevens

"He believed in democracy, justice for all and a chance for everybody," she said.

Maria attended the service with her four children, including two-year-old twins.

John Osborne, who was abducted when he tried to rescue Mr Stevens from war veterans and was present when his friend was killed, also attended.

Maria Stevens attended the service with her children

With his right eye still blackened and breathing with difficulty because of a collapsed lung from the beating he received, he said only:"It's over and I'm fine."

Mr Steven's service was originally intended to be a small family affair at his children's school, but it has taken on a wider national significance as the violence continues.

Tobacco disruption

On Monday, squatters and war veterans set fire to tobacco crops grown on white-owned farms just to the east of Harare.

Reports say they were taken to the land on buses shortly before the fires started. The farmers had earlier received warnings to leave their property.

Tobacco famers lost their crops

A spokesman said tobacco storage barns had been set alight, destroying the farm's entire crop of 110 tonnes.

Farmers have expressed concern that the political violence will delay Wednesday's scheduled opening of tobacco auctions and deter foreign buyers, dealing another blow to the country's collapsing economy.

Zimbabwe is the world's second biggest tobacco exporter, and the product is the nation's largest source of hard currency.

But this year, the amount of tobacco delivered to the auction floors is down sharply.

Officials of the Commercial Farmers Union, which represents many white farmers, said the grading and packing of tobacco had been severely disrupted by the farm occupations.