Ivory Coast's president vowed Monday that those responsible for hundreds of killings last year in the country's west will be punished, although he did not mention that human rights groups accuse his supporters of committing the atrocities.

A U.N. investigation has established that "at least 505 people" were killed in Duekoue and surrounding villages following the disputed presidential election.

In his first visit to the area since his inauguration last May, President Alassane Ouattara told crowds he has been "revolted" by the crimes committed. He said he was particularly moved to be visiting Duekoue given the "major clashes, the killings that took place here."

"The murderers will be punished," he said, noting that a commission set up more than six months ago was investigating postelection crimes. "The investigations are under way to shine the light on crimes, especially those committed in this region."

Ivory Coast headed to the brink of civil war in early 2011 after then-President Laurent Gbagbo refused to concede defeating after losing the presidential runoff vote to Ouattara.

While more than 100 Gbagbo supporters have been charged with postelection crimes in Ivory Coast, no one from Ouattara's side has been charged, though the U.N. and human rights groups say both sides carried out killings and rape.

During the political standoff, Gbagbo's forces and pro-Gbagbo militia groups razed immigrant and Muslim neighborhoods in Abidjan, using heavy artillery, tanks, grenades and tear gas against civilians perceived to be Ouattara supporters.

Gbagbo is facing charges of war crimes and crimes against humanity at The Hague.

In March 2011, Ouattara, who is Muslim and hails from the north, enlisted the help of the former northern rebels, who began a violent takeover of towns on their push south to Abidjan.

The town of Duekoue, home to many who supported Gbagbo, became a symbol of horrific violence.

Human rights groups say that on March 29, 2011, Ouattara's forces and traditional hunters called "dozos," who also hail from the north, combed through the Carrefour neighborhood in Duekoue.

The fighters went door to door, pulling men out of their homes and shooting them or beheading them with machetes, according to a U.N. report. Women, children and elderly people were also among the dead.

U.N. investigators found evidence that some victims were killed as they were tried to flee or hide. Bodies were dumped in wells in the neighborhood, and the number of victims would later be impossible to determine due to decomposition.

Shells of brick homes sit unoccupied in the Carrefour neighborhood across the dirt road from a mass grave, now covered in grass more than a year after the massacre.

The ICC has visited Duekoue to confirm the existence of mass graves here. The deputy prosecutor of the ICC, Fatou Bensouda, has said the Ivorian government is continuing to cooperate with the investigation even as it probes both sides.

Resident Constant Bohe, who runs a group for those who returned after the violence ended, said he is waiting for the government to prosecute those responsible.

"We are committed to the road to reconciliation, mutual forgiveness, but especially, to truth," Bohe said. "It's not normal to undergo a massacre and then, well, we don't know the truth, and life goes on. It's not about vengeance."

Bohe was among the thousands who crowded the town square on Monday to hear Ouattara speak. The president arrived with nearly 100 new SUVS for people in the region, and said he also would put an end to power and water cuts.

"We supported the former president," said Tiehoulou Guei, 18, a student. "But now we are trying to work with the new president. (Ouattara) is a president who wants to work."