Thousands of opposition and rebel supporters in Ivory Coast have held a memorial service for those killed in a security crackdown on a demonstration last month.

About 10,000 people gathered in a sports stadium in the Treichville neighborhood of Abidjan Saturday, holding Christian and Muslim prayers for those who died when an opposition protest was aborted by security forces on March 25.

An opposition leader, Alphonse Djedje Mady, said the demonstrators were assassinated while seeking liberty.

He says it will never be known how many were killed. The opposition says several hundred people died during several days of violence and raids that followed the attempted march. But the government claims the toll was 37, including several policemen.

President Laurent Gbagbo had banned the march last month, saying it was a renewed attempt to overthrow him. However, he allowed Saturday's memorial service.

Many chanting in the crowd Saturday called President Gbagbo a murderer.

Several thousand French and recently arrived U.N. troops are deployed along the north-south front line. Most of those in the march welcomed the presence of the United Nations. One was a young opposition militant, Alamba, who says he was beaten during the attempted march last month.

"We are very happy, because we see the situation of the security," he said. "Let's say, it's very very good. The security came from abroad, United Nations. We are very happy today. Today is a free day, it is a peace day."

Several scuffles broke out when demonstrators said they recognized undercover security forces in the crowd. Protesters also taunted the few Ivorian policemen who helped U.N. troops ensure security.

Protest organizers say Ivorian security forces prevented some militants from joining the protest by blocking main arteries. But they were satisfied that thousands showed up, saying it was quality that mattered rather than quantity.

A counter-demonstration by youth groups close to Mr. Gbagbo, which had been planned for Saturday, was delayed until Sunday to avoid possible street violence between rival militants.

Opposition supporters say Mr. Gbagbo is blocking full implementation of the power-sharing peace deal signed in France 16 months ago, while the presidential camp has called on the northern-based rebels to disarm immediately.