Officials say that the New Year's stampede in Ivory Coast which killed 64 people was caused by a combination of several factors including unofficial tree trunk barricades, the narrowing of a major thoroughfare, bad lighting and a shortage of police officers.

Abidjan prosecutor Simplice Kouadio announced the preliminary findings of a police investigation on state television Saturday night.

According to the report, a "human wave" of people leaving a New Year's fireworks display was confronted by a group of people going in the opposite direction on the Boulevard de la Republique by the Houphouet Boigny stadium.

Police interviewed 31 people including the injured, families of victims, firefighters, doctors, the district governor of Abidjan and the Commissioner of Police. The prosecutor said criminal proceedings will be initiated against any perpetrators.