Mystic — Stonington Police charged a Groton man early Monday morning with first-degree assault after they say he struck a man in the head with a club-like object in the parking lot of the Hyatt Place hotel on Route 27.

The victim suffered a serious head injury, according to police, and was taken to Lawrence + Memorial Hospital. Police did not have an update on his condition.

Jonathan A. Valladras, 26, of Meryl Court, Apt. 16, also was charged with breach of peace and carrying a dangerous weapon after the 1:28 a.m. incident. He was arraigned later Monday in New London Superior Court.

According to police, the two men had been involved in a long-running conflict when Valladras confronted the victim, who worked at the hotel, in the parking lot. Police are continuing to investigate the incident.