According to initial reports, at least five people were shot and have been taken to hospital, with an unconfirmed number of victims requiring surgery.
Officers from a number of police agencies, including New York state troopers, flocked to the scene at around 2:40 a.m. ET.
A large part of downtown Rochester has been shut down by law enforcement officers.
Witnesses claim a large group of people had gathered at MLK Park for a party, with shots being fired a while after they had arrived.
No deaths have as yet been reported, although the crime scene remains active with a large police presence continuing to investigate the incident.
