ABIDJAN, Ivory Coast - African Union mediators intervened Sunday in Ivory Coast's growing political crisis after both presidential candidates emerged from a disputed election to say they were victorious.

In Bouake, stronghold of opposition candidate Alassane Ouattara, several hundred people marched down a main boulevard Sunday afternoon, calling for incumbent Laurent Gbagbo to stand down. Villagers wielding machetes also created a checkpoint in protest along one major road in the region.

"It's important not to have violence, not to return to war - to find a peaceful solution," former South African President Thabo Mbeki said Sunday after arriving in Abidjan to try to mediate at the behest of the African Union.

The international community has recognized Ouattara as winner of the runoff vote held one week ago.

That did not stop Gbagbo from defying calls to concede. On Saturday, he wrapped himself in the Ivorian flag as he was sworn in for another term at the presidential palace. Hours later, Ouattara told reporters that he, too, had been sworn into office.

That effectively set up parallel governments and raised serious questions about who was in charge of this West African nation, the world's largest cocoa producer, which was split into a rebel-controlled north and a government-controlled south during a 2002-03 civil war.

While Ouattara has international backing, Gbagbo holds key elements of power, including the army and state media.

Their support falls along geographical lines, with Gbagbo controlling the south and Ouattara the north. That has led to speculation that each may govern his half of the country, which officially reunited in a 2007 peace deal.

Revised results released Friday showing Gbagbo won reelection did not include a half-million votes cast in the north. The constitutional council said that was because pro-Gbagbo voters there had been intimidated.

That infuriated residents in areas where votes were thrown out, some of whom blocked a major road Sunday with tree trunks and rocks.

National identity remains at the heart of the split: Northerners, mostly Muslim, have long complained that they are treated as foreigners in their own country by the mostly Christian southerners.