At least 35 children were killed and six others critically injured in a crowd crush at a funfair in southwest Nigeria on Wednesday, police said.

Eight people have been arrested for their alleged involvement in the incident at the Islamic school in the city of Ibadan, an Oyo state police spokesperson said in a statement Thursday.

The event’s main sponsor is among those detained, police said.

According to local radio station Agidigbo FM, the organizers of the event – identified as the Women in Need of Guidance and Support (WING) – expected to host 5,000 children under the age of 13 at the free event, where they could win prizes like scholarships.

Nigerian President Bola Tinubu expressed his condolences through a statement from his spokesperson, state news agency NAN News reported.

“In this moment of mourning, President Tinubu stands in solidarity with the affected families and offers prayers that the Almighty God will grant peace to the souls of those who have departed in this unfortunate event,” the statement said.

The president also urged the Oyo State Government to take necessary steps to prevent a similar tragedy from occurring, according to NAN.

Oyo State Governor Seyi Makinde said it was “a very sad day.”

“We sympathise with the parents whose joy has suddenly been turned to mourning due to these deaths,” Makinde posted on Facebook.

“I want to reassure our people that anyone directly or remotely involved in this disaster will be held accountable. Please remain calm as the security agencies investigate this unfortunate incident.”

The case has been transferred to the homicide section of the state’s criminal investigation department, police said.

“The Oyo State Police Command sympathizes with all the families and loved ones affected by the tragedy and assures the good people of the state that justice will be served accordingly,” the police spokesperson said.

Nigeria, a West African nation home to more than 236 million people, has seen several deadly crowd crushes in recent years.

In February, the Nigeria Customs Service confirmed that an unspecified number of people were trampled to death during a crowd surge as they waited for discounted rice at its office in Lagos, the country’s largest city.

Many children were among 30 people killed in a crowd crush at a church event in the southeastern city of Port Harcourt in 2022, according to police and security officials.