Two of the four men who escaped Newark's Delaney Hall immigration detention center last week remain missing, the FBI says.

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.

A dramatic escape from Newark’s Delaney Hall detention center has authorities on alert, with two detainees recaptured and law enforcement searching for the other two.