At least 60 people were killed and more than 200 injured after the early-morning fireworks display turned into a panicked stampede near the 65,000-capacity Felix Houphouet Boigny Stadium in Ivory Coast's commercial centre, reports say.
The majority of those killed were between eight and 15 years old, said Col. Issa Sako, of the fire department rescue team.
Thousands gathered at the stadium to see the fireworks, and after the display, the crowds moved out onto the Boulevard de la Republic by the Hotel Tiama, said Sako, on Ivory Coast state television.
Government investigating cause
"The flood of people leaving the stadium became a stampede which led to the deaths of more than 60 and injured more than 200," said Sako.
BBC reports 60 deaths, while The Associated Press puts the death toll at 61. But the number of dead is expected to rise, reports say.
The cause is unknown, with mixed reports about what sparked the deadly stampede.
According to the BBC, some reports indicated the stampede started as thousands tried to leave the stadium at the same time as another large group arrived.
But Reuters, citing one of the injured, says the New Year's Eve crowd panicked when security forces arrived on scene, triggering the stampede.
The government is investigating the incident, say officials.
Ivory Coast President Alassane Ouattara visited the scene of the stampede early Tuesday.
He also saw some of the wounded in hospital, and pledged that his government would pay for the costs of their medical treatment, according to the president's office.
Parents still looking for kids
Ouattara's government organized the fireworks to celebrate Ivory Coast's peace, after several months of political violence in early 2011 following disputed elections. It was the second year that Abidjan had a New Year's fireworks display.
Desperate parents went to the city morgue, the hospital and the stadium to try to find children who were still missing.
Mamadou Sanogo was searching for his nine-year-old son, Sayed.
"I have just seen all the bodies, but I cannot find my son," said a tearful Sanogo. "I don't know what to do."
Hours after the stampede, soldiers patrolled the site, where victims' clothes, shoes and other debris littered the street.
Footage on state TV showed a woman crying in the back of an ambulance, and another woman on the side of the street, bent over and apparently in pain. It also showed small children in a hospital, some in bandages.
This is the third stadium tragedy in Ivory Coast since 2009.
- In 2009, 22 people died and more than 130 were injured at an overcrowded Houphouet Boigny stadium in a stampede during a World Cup match. FIFA fined the nation's soccer federation tens of thousands of dollars.
- A year later, two people died and 30 were injured in a stampede at a municipal stadium during a reggae concert in Bouake.