HOPEWELL, Va. (WRIC) — The search is still on for four inmates who escaped a federal prison camp overnight in Hopewell.

Corey Branch, Tavares Graham, Lamonte Willis and Kareem Shaw were all discovered missing around 1:45 a.m. on Saturday, June 18.

Authorities said the four prisoners walked away from the Federal Correctional Complex Petersburg’s satellite camp early Saturday morning.

The Bureau of Prisons website said its satellite camps around the country, which are often adjacent to or adjoining to the prison’s main building, provide inmate labor to the main institution and to off-site work programs.

The satellite camp houses 185 prisoners in the FCC Petersburg’s minimum-security facility, this morning’s escape sparked an internal investigation.

The United States Marshals Service, Federal Bureau of Investigation and other law enforcement agencies have been notified of the prisoners’ escape and are taking part in the search.