Zimbabwe's presidential elections - in 60 seconds

Zimbabweans go to the polls on 31 July to elect a president and parliament in an election that could mark the end of the troubled coalition government between veteran President Robert Mugabe and Prime Minister Morgan Tsvangirai.

Mr Mugabe, leader of Zanu PF, is seeking to extend his 33-year rule.

His main rival is Mr Tsvangirai, who helped form the Movement for Democratic Change (MDC) in 1999 and has been Mr Mugabe's only credible challenger at the polls since independence in 1980.

There are five presidential candidates, with Mr Mugabe, 89, and Mr Tsvangirai, 61, being the front-runners.

BBC Africa's Patience Chinwada explains the importance of these elections.