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.

Four detainees escaped when tensions boiled over at the U.S. Immigration and Customs Enforcement facility known as Delaney Hall on Thursday in Newark, the Department of Homeland Security confirms. ICE told lawmakers they got out through a hole in a wall.

Federal officials have apprehended one of the four escaped detainees who went missing from an immigration detention center in New Jersey earlier this week.