Morgan Tsvangirai and his wife Susan are shown in Harare in 2003. Tsvangirai became prime minister of Zimbabwe after months of negotiations between his party and President Robert Mugabe's ZANU-PF party. (Associated Press)

Morgan Tsvangirai's wife, Susan, was killed and the Zimbabwean prime minister was in hospital Friday following a car crash outside Harare, Movement for Democratic Change party officials say.

Tsvangirai, his wife and an aide were travelling to a weekend rally in his home region, south of the capital, when the car side-swiped a truck, his spokesman James Maridadi told reporters.

Officials from Tsvangirai's Movement for Democratic Change party, speaking on condition of anonymity, said Susan Tsvangirai had died and that an official statement would come later from the family.

According to reports, the 56-year-old prime minister suffered only minor injuries.

President Robert Mugabe, who recently formed a unity government with rival Tsvangirai, visited the prime minister in hospital in Harare, said an Associated Press reporter.

Earlier in the day, British Prime Minister Gordon Brown sent his condolences to the prime minister.

The Tsvangirais, parents of six children, had been married for 31 years.

A former trade union leader, Tsvangirai won the most votes in the first round of the presidential election last March, but pulled out of a run-off with Mugabe because of violence against his supporters.

Tsvangirai's Movement for Democratic Change and Mugabe's ZANU-PF party held months of negotiations before finalizing details of the new government, which is faced with a collapsed economy and a growing health crisis.

Zimbabwe's unemployment rate hovers around 90 per cent and the inflation rate is estimated to be more than 230 million per cent.

Roughly half of the country's population — six million people — need food aid, and a widespread cholera outbreak has killed as many as 4,000 people.

With files from the Associated Press