At least 61 people have been crushed to death and more than 200 injured in a stampede outside a stadium in Ivory Coast's main city of Abidjan after a New Year's Eve fireworks display, the government has said.

Witnesses said on Tuesday that police had tried to control crowds around the Felix Houphouet Boigny Stadium following the celebrations, triggering a panic in which scores were trampled.

"The flood of people leaving the stadium became a stampede which led to the deaths of more than 60 and injured more than 200," Issa Sako, the head of military rescue workers, told Ivory Coast state TV.

"The estimate we can give right now is 49 people hospitalised ... and 61 people dead," he said.

President Alassane Ouattara, visiting injured people at the hospital, called the incident a national tragedy and said an investigation was under way to determine what happened.

"I hope that we can determine what caused this drama so that we can ensure it never happens again," he said.

Sako told public television that most of those killed were between 8 and 15 years old.

"In the crush, people were walked over and suffocated by the crowd," he said.

Thousands had gathered at the stadium in Abidjan's Plateau district for the New Year celebrations which was organised by the government to celebrate peace after several months of political violence last year.

'Children still missing'

Sanata Zoure, a market vendor injured in the incident, said New Year's revellers going home after watching the fireworks had been stopped by police near the stadium.

"We were walking with our children and we came upon barricades, and people started falling into each other. We were trampled with our children," she said.

Another witness said police arrived to control the crowd after a mob began chasing a pickpocket.

Images broadcast by RTI television showed bodies stretched lifeless on the ground. Piles of abandoned shoes and clothing could also be seen at the stadium, where soldiers and police were deployed.

Desperate parents went to the city morgue, the hospital and to the stadium to try to find children who are 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.

"My two children came here yesterday. I told them not to come but they didn't listen. They came when I was sleeping. What will I do?" said Assetou Toure, a cleaner.

The incident was the worst of its kind in Abidjan since 2010, when a stampede at a stadium during a football match

killed 18 people.

Ivory Coast, once a stable economic hub for West Africa, is struggling to recover from a 2011 civil war in which more than 3,000 people were killed.