Migrants clashed with police at a detention center in northern Greece, with 35 people escaping the facility after cutting through a perimeter fence before authorities recaptured nearly half of them, police said Sunday.

The incident took place at the temporary accommodation center in Sintiki, a few kilometers from Greece's border with Bulgaria. Police said they called in reinforcements after migrants threw rocks at officers during the confrontation.

Authorities used flash-bang grenades as the clashes continued into the early hours of Sunday. At least five migrants were injured and taken to a hospital for treatment.

Police said 35 migrants managed to leave the facility after breaking through the perimeter fence. Officers subsequently detained 17 of them, while the search continued for the remaining 18.

The center currently houses around 450 people whose asylum applications are being processed. Such procedures can take a considerable amount of time, leaving migrants in temporary accommodation for extended periods.