A western Pennsylvania amusement park increased security after disturbances involving several large groups of teenagers prompted the park to end its opening day early.
Police in West Mifflin near Pittsburgh said the incidents at Kennywood Park were reported at about 8:30 p.m. Saturday, and the park closed a half-hour later.
Police said the crowd of young people pushing, shoving and running through the park was dispersed by officers from several responding departments.
Park spokesman Nick Paradise said security officers reported four teenage girls with bruises and other minor injuries.
The park's website says Kennywood is usually open until about 10 p.m. depending on crowd size and weather conditions.
The 117-year-old park known for its trio of historic wooden roller coasters was scheduled to be closed Sunday and will reopen next Saturday.
Park officials announced the increased security measures
