SOMERSET, Pa. -- A Somerset man has been charged with abusing his girlfriend's 1-month-old grandson.

Jeremy Smith is accused of injuring the baby during a fight with his live-in girlfriend, Mary St. Clair, on Jan. 1. Police said Smith punched, kicked and threw St. Clair to the ground while she was caring for the baby.

During the altercation, police said Smith attempted to pull the baby from St. Clair's arms. As a result, the boy suffered a broken arm, broken leg, skull fracture and broken nose.

Police learned of the boy's injuries after he was treated at Children's Hospital on Jan. 30. The baby's parents were questioned and after talking to St. Clair, the parents were made aware of the Jan. 1 incident.

Smith is being held in the Somerset County Jail. He faces charges of aggravated assault, simple assault, recklessly endangering another person and endangering the welfare of a child.

He is expected to be arraigned sometime Thursday.