Zimbabweans are going to the polls today to choose a president, parliament and local councils. The elections come amid a severe economic crisis, as we hear from Scott Bobb in Southern Africa Bureau in Johannesburg.

Zimbabweans began lining up outside polling stations before dawn Saturday hoping to cast their ballot early. The elections were seen as a choice between keeping in power the government of President Robert Mugabe, who has ruled since independence 28 years ago, and regime change advocated by two opposition candidates, Morgan Tsvangirai and Simba Makoni.

Zimbabwe police Chief Augustine Chihuri warned against any violence before or after the vote.

"All the defense and security forces of Zimbabwe are on full alert from now onwards covering the election period and beyond," said Chihuri.

Soldiers and police put on a show of force patrolling the capital, Harare, in a convoy of armored personnel carriers and water cannon trucks.

Nearly six million voters are registered to vote at one of more than nine thousand polling stations. They are to choose a president, 210-member national assembly, a newly created senate and local councils.

Opposition leaders and pro-democracy groups have expressed concern over what they say are irregularities that could be used to rig the vote.

The say they have evidence that voter registration lists have been inflated and that 50 percent more ballot papers have been printed than registered voters. They say the widely feared police are allowed inside polling booths.

They also say that the four simultaneous elections, each with its own ballot, will likely confuse many voters because of a lack of voter education programs prior to the vote.

However, Mr. Mugabe dismissed these allegations as he voted Saturday saying his government is not in the habit of rigging and his conscience would not allow him to do so.

Most Zimbabweans are suffering from an economic crisis characterized by hyper-inflation, 80 percent unemployment and shortages of food, fuel and many basic goods.

The winner of the presidential election must receive 51 percent of the votes cast. Otherwise, he must stand against the second-placed candidate in a run-off election within three weeks.