Police said a crowd of about 500 people outside several apartment buildings Saturday became unruly, blocked a street, and threw beer cans and bottles at officers when they tried to disperse the crowd. Deputy Chief Rene Kelley said in a news release that police were called to Madbury Court by several residents and were met with a barrage of beer bottles and cans. One officer was hit on the side of the head and officers withdrew and called for backup. Kelley said the crowd threw another round of bottles and cans, and officers used pepper spray before people began leaving. Kelley said Jordan M. Mahar, 21, of Wolfeboro, was arrested on charges including assault on a police officer. Mahar was being held in jail on $5,000 cash bail.