PORTLAND — A corrections officer at the Cumberland County Jail has been arrested on a charge of assaulting his girlfriend.

Portland police Lt. Robert Ridge said a witness saw 49-year-old Thomas Lano of Old Orchard Beach fighting with his girlfriend Saturday night on Congress Street, near the Dogfish Cafe.

The witness followed Lano and the woman, who drove to South Portland. Police stopped Lano on Main Street, where he was arrested by Portland police.

Lano was charged with domestic violence assault, a misdemeanor, at the Cumberland County Jail.

He has since been released on $100 cash bail.