From: News 12 Staff Nassau police are investigating a major riot at the Roosevelt Field Mall. The detectives of the crime scene unit are located on the south side of the parking lot of the mall. Some police officers seem to be looking under some vehicles. K-9 units have also been observed at the site. Nassau police say the incident happened around 4 p.m. They say there may have been a big fight inside the mall. There have also been reports of the use of a knife or weapon in the incident, but this has not yet been confirmed. Police say people panicked and ran out of the mall and some stores went into lockdown. Police say there are no reports of injuries so far. A social media user posted on Twitter that it was an absolutely “scary event”. He said he heard the sound of people running, screaming, crying and that he never wanted to experience it again. Other people at the scene said News 12 Long Island that buyers panicked at what some say was a loud sound they thought was a shot, but that is unconfirmed.