AUBURN – Dozens of Army Reserve doctors, nurses and medics left Maine on Thursday in preparation for deployment to Iraq.

The 399th Combat Support Hospital is the second combat hospital unit from New England sent to Iraq. The unit is based in Taunton, Mass., and consists of about 450 soldiers, more than 50 of whom come from Maine.

The Maine group left the state by bus Thursday afternoon. A mobilization ceremony will be held in Boston on Saturday, according to Linda Jeleniewski, spokeswoman for the 94th Regional Readiness Command.

The unit will spend one to three months training in Wisconsin before being sent overseas. The deployment could last up to 18 months, Jeleniewski said.

While in Iraq, the unit will serve as a mobile hospital, treating soldiers and civilians.

The combat support hospital is the present-day equivalent of the former mobile Army surgical hospital or M.A.S.H. unit.