The first team of foreign observers has been arriving in Zimbabwe ahead of the presidential election later this month.
Simba Makoni is challenging Mr Mugabe for the presidency
The state-run Herald newspaper said at least 50 observers from the regional body, the Southern African Development Community, were in the capital, Harare.
The Zimbabwean government has invited 47 countries and organisations to observe the 29 March poll.
But it is not allowing observers from Western countries critical of President Robert Mugabe into the country.
"We are here because Zimbabwe is a member state so we need to take ownership of these elections," Sadc's Tanki Mothae was quoted as saying by the paper.
The presidential election will see Mr Mugabe pitted against former Finance Minister Simba Makoni and long-term opposition leader Morgan Tsvangirai.
Legislative elections are also taking place.
An independent election monitoring group has warned that there will be too few polling stations in the cities, where the opposition has most support.
According to the Zimbabwe Election Support Network, the number of registered voters per polling station in Bulawayo and Harare is more than twice that of the other provinces.
It allows an average of 22 seconds for each registered voter in the capital to take part, the group said.
The group warned that, unless the number of polling stations is increased, voters are likely to be turned away when the polls close - as happened in the 2002 presidential election.
On Monday, the European Union expressed concern about the fairness of the polls.
Western monitors and the Zimbabwean opposition have accused President Mugabe of rigging previous votes.
On Monday, a man was jailed for a month for destroying an election poster of Mr Mugabe.
The magistrate said his behaviour could have provoked violence and jailed him until after the election.