Up to 87 000 uniformed forces and electoral officials are to begin casting their votes on Sunday in a two-day special vote ahead of July 31 general elections.
The Zimbabwe Electoral Commission says 209 polling stations have been set up across the country to cater for the early vote for officials who will perform duties outside their wards on July 31.
Close to 7 000 police officers and 15 000 election officers and 200 soldiers are among those voting on Saturday. Electoral officials have allayed fears of vote rigging, saying the elections will be conducted in the presence of all political party agents. Ballot boxes are to be sealed by all parties before being forwarded to the wards for counting.
Meanwhile, the African Union is to send a 60-member observer team headed by former Nigerian President Olesugun Obasanjo to Zimbabwe's elections later this month.
Amnesty International released a report saying Zimbabwean police are continuing to target and intimidate human rights defenders ahead of elections.
Zimbabwe's past elections have been marred by intimidation, disputes and allegations of vote rigging.
This led to an acrimonious unity government led by President Robert Mugabe and his long time rival Morgan Tsvangarai.
The deployment of Obasanjo will be seen as the continent showing concern for the credibility of the elections. Obasanjo and his team will arrive ten days before the elections, bolstering a nine member team that has been on the ground since June 15.