Four detainees have escaped from a federal immigration detention center in New Jersey, which has been the center of protests since its opening in May and where both a sitting congresswoman and Newark’s mayor have been arrested.

More law enforcement has been brought in to find the detainees missing from Delaney Hall. DHS identified the escapees as two Colombian men and two Hondurans.

Protesters outside a New Jersey federal immigration detention center locked arms and pushed against barricades as vehicles passed through gates and Newark’s mayor cited reports of a possible uprising and escape as disorder broke out at the facility.