A 24-year-old Fairfield woman accused of punching a man in the face outside Chip's Family Restaurant because he believed she was intoxicated and blocked her car from leaving was arrested Saturday evening.

Adalys Sierra, of Tunxis Hill Road, was charged with breach of peace and illegal possession of a controlled substance.

Police said a 55-year-old Oxford man saw Sierra leave Chip's and, after a disturbance in the parking lot, thought she looked intoxicated. He then positioned his pickup truck to prevent her from driving off, according to the report.

"She began screaming and telling him to move," said police Lt. James Perez. "She became increasingly angry, walked up to him and punched him in the face. He did have redness on his face, but no other obvious sign of injury. He stated that his nose hurt."

Perez said Sierra stated that she became angry with the Oxford man "and felt her actions were completely justified."

Police requested assistance for a search from Westport's K-9 police dog, who was on duty at the time, and the dog indicated something suspect was in Sierra's purse. Officers found five Vyvanse pills which were not prescribed to her, police said. The pills are used to treat Attention Deficit Hyperactivity Disorder.

The car Sierra had driven was towed from the scene, police said.

She was released on a promise to appear Sept. 29 in Bridgeport Superior Court, police said.