Protestors have locked themselves to the bus to stop it from moving forward.
TUCSON, AZ - Police have arrested 18 people after an immigration protest in Tucson stopped a bus carrying detainees and blocked entry into the federal courthouse's parking lot.
A dozen demonstrators used chains and pipes to lock themselves to the wheels of the bus Friday morning.
Tucson police used power saws to free the demonstrators and get the buses back on the road.
Police say all 18 people -- ranging in age from 21 to 68 -- were arrested on hindering prosecution charges.
About 80 immigrant rights activists were trying to halt court proceedings that lead to deportations.
Shortly after noon Friday, federal officials canceled deportation hearings in the Tucson courthouse for the day.
Implemented in Tucson in 2008, Operation Streamline was supposed to fast-track up to 100 prosecutions of immigrants daily.