A 9-year-old Palestinian child was found dead on April 25 at a refugee camp in the city of Antwerp in Belgium, local media reported.
The child went missing on Monday evening in Broechem town while out cycling at the camp, according to the report.
Police started a murder investigation and five suspects were arrested.
"I wish to express my sincere condolences on the tragic death of a child. An investigation will be conducted in a transparent and independent manner. The guilty must be punished," Belgian Prime Minister Charles Michel said on Twitter.
The boy, born in Lebanon and of Palestinian nationality, was staying with his 26-year-old mother in the Broechem asylum centre when he disappeared on Monday evening, Aerts said.
A search operation found the boy's lifeless body in a ditch on the grounds of the reception centre on Wednesday afternoon.
Belgium, a country of about 11 million inhabitants, receives about 20,000 asylum seekers annually, many of whom come from conflict areas in the middle East, according to the Fedasil agency website.