A young man suffered serious injuries when an explosion went off in Central Park Sunday morning, according to multiple reports.

A senior law enforcement official, who was not identified, told WNBC the explosion appeared to be a fireworks-related accident, although friends of the injured man denied they were playing with fireworks.

The New York Police Department is investigating to determine what caused the blast. A bomb-sniffing dog was on the scene Sunday.

Reports initially claimed Central Park was partially closed by the blast, although NYPD spokesman J. Peter Donald refuted the reports.

Authorities were called to Central Park near Fifth Avenue and East 62nd Street just before 11 a.m. Sunday after a large explosion was heard in the area, WABC reported. Eyewitnesses told the news station the victim stepped on something as he was walking and it blew up.

The victim was with a group of three men from the Washington, D.C. area, according to WCBS. The victim was identified as 18-year-old Connor Golden.

Medics took the man to a hospital for treatment. Firefighters described his injuries as a “possible amputation,” according to WABC.