Belgian police shot and killed Halit Altun, a 42-year-old Turkish citizen and father of four who was reported to have attacked someone with a knife, in Eupen on Sunday after a fight between children grew into a clash involving about 50 people.

Altun had lived in Belgium for some 15 years and worked at a cable factory, Turkey’s İhlas News Agency (İHA) reported.

The dispute began among youngsters from Altun’s family and the children of families of Russian and Ukrainian origin who knew one another from school and had been playing together in Scheiblerplatz park, Belgian broadcaster BRF reported.

Adults then joined the dispute.

Four officers arrived at about 6:30 p.m. and tried to calm the crowd with pepper spray, the GrenzEcho newspaper reported.

Altun picked up a knife, moved toward the other group and wounded a person who tried to stop him, the Eupen prosecutor’s office said, although Altun’s family denies prosecutors’ claim that he attacked someone with a knife.

An officer then fired two shots at Altun, who died from his wounds, prosecutors said.

Hayat Karim, a lawyer for Altun’s widow, denied the prosecutor’s account and told Belgian state broadcaster RTBF that Altun was unarmed when the police shot him.

Altun’s uncle, Cihad Öğüşlü, said he had been trying to protect his children and alleged that police handcuffed him after the shooting and that an ambulance arrived about 40 minutes later, claims that have not been independently verified.

The Standing Police Monitoring Committee (Committee P), Belgium’s external police watchdog, is investigating the officer’s use of deadly force, while federal police are conducting a separate investigation into the clash and alleged knife attack.

Police had identified about 30 witnesses by Monday and asked others to provide accounts or cellphone footage of the incident.