The leader of the opposition Movement for Democratic Change, Morgan Tsvangirai, was assaulted yesterday in Chivhu, about 80 km south of the capital, Harare.
The incident happened as Mr Tsvangirai and his wife were on their way to their country residence in Buhera, accompanied by two bodtyguards.
The former trade union leader has been on trial since February 2003 for alleged treason over a supposed plot to eliminate President Mugabe. He faces the death sentence, if found guilty.
He also faces another treason charge over a call made in June 2003 to his supporters to topple a democratically elected government.
The date of the trial over the second treason charge has not yet been fixed.
Celebrations were held in Zimbabwe yesterday to mark the 80th birthday of President Robert Mugabe.
