Updated

Ivory Coast's president on Friday said no one is above the law and vowed to investigate all war crimes committed in the five months following last year's election — including massacres blamed on fighters loyal to him.

Alassane Ouattara told reporters during a state visit to Senegal that he only accepted the help of a former rebel army on March 17, more than three months after he was declared the winner of last November's election. Ouattara spent those months imprisoned inside a hotel because the country's entrenched ruler, Laurent Gbagbo, refused to leave office.

Gbagbo was finally toppled in April, after the armed group swept across the country in a two-week campaign marred by reports of massacres. United Nations investigators said at least 330 people were killed in the western town of Duekoue, where reporters saw bodies at the bottom of wells and where the smell of death still hovers over the vegetation where corpses were dumped.

"We want to end impunity in Ivory Coast," Ouattara said. "No one is above the law. All those that committed crimes of blood will be punished ... There will be no exceptions."

In Ivory Coast, a three-day period of mourning is being observed to honor the dead. At least 1,000 people were killed in the postelection violence, first by the army under Gbagbo's control and later by the soldiers fighting to install Ouattara, whose victory in last year's poll was recognized by the U.N., the United States and the African Union.

The 68-year-old leader said he only accepted the help of the armed group after it became clear Gbagbo would only leave by force.

"I need to tell you that in reality the Republican Forces were only constituted on the 17th of March because I realized that we were in a phase where things had dragged on for too long," he said.

The fighters took less than a week to sweep across the Poland-sized nation and reach the outskirts of Abidjan, the commercial capital that is home to the presidential palace and the hotel where Ouattara was holed up.

Ouattara told reporters Friday that he expected Gbagbo to accept defeat once he realized he had lost control of the countryside, but the strongman sealed himself inside an underground bunker accompanied by over 100 of his closest aides including his ministers, his gardener, his wife and his grandchildren.

He was arrested April 11 after French special forces used Mi-24 attack helicopters to destroy the tanks and arsenal that Gbagbo had positioned outside his bunker, allowing Ouattara's forces to rush in. He is now under house arrest in a village in the country's north awaiting trial. His ministers and closest aides are under house arrest in a hotel in Abidjan.

Ouattara said he dispatched a prosecutor to Duekoue one week after the massacre, and has also asked his government's human rights commission to send a team to investigate. He said he has also ordered an inquiry into the April 27 killing of a popular fighter called Ibrahim Coulibaly, or IB, who was rumored to have presidential ambitions.

IB's fighters initially joined the battle to oust Gbagbo, only to then clash with Ouattara's soldiers during the final days of the military campaign. IB's top aide said the 6-foot-6 (1.98-meter) fighter — who years ago was one of Ouattara's bodyguards — was shot in the heart by soldiers under the command of Ouattara's prime minister.

"My instructions were clear: Human life is sacred," said Ouattara. "There will be an investigation. ... IB was one of my bodyguards. He was a boy that was part of my household. We know him well — his wife, his children. So I cannot remain indifferent to his death."