At least two people were killed and many others were injured in the capital of the Democratic Republic of Congo on the last day of political campaigning ahead of Monday's national elections.

Police in Kinshasa banned political rallies Saturday after supporters of the incumbent, President Joseph Kabila, clashed with those supporting his main rival Etienne Tshisekedi.

President Kabila canceled his rally, but Mr. Tshisekedi vowed to defy the ban and hold his rally in Kinshasa's largest stadium. Thousands of people gathered at the Kinshasa airport to meet him on arrival, but police prevented his entourage from leaving the airport.

Security troops used tear gas and water cannon to disperse the crowds. Witnesses reported hearing gun shots and seeing bodies.

Earlier Saturday police used force to disperse crowds in central Kinshasa. Sporadic gun shots were heard throughout the day and plumes of smoke billowed in several places.

In previous campaigning, supporters of the two politicians have clashed in the capital and in the country's second-largest city, Lubumbashi.

Ten candidates are challenging President Kabila in Monday's presidential election, and more than 18,000 people are running for 500 seats in the national assembly.

Political analysts in Congo believe Mr. Kabila will win re-election, partly because much of the opposition vote will be split among three candidates.

The United States, European Union and United Nations have expressed concern about election-related unrest and violence, and the International Criminal Court has said it will prosecute any perpetrators of election-related crimes.

Mr. Kabila has been president since 2001, when he took office after the death of his father, Laurent. He won the country's last presidential election in 2006.