Marlborough — An 18-year-old suffered serious injuries Sunday night when an object that had been placed in a bonfire exploded, according to state police.

State police from Troop K in Colchester and an ambulance crew were dispatched at 9:45 p.m. for a reported explosion at 342 Jones Hollow Road.

They found Robert Hill, 18, of 7 Finley Road suffering from serious abdominal and other injures as a result of the explosion.

While medical responders rendered first aid, troopers searched for other victims. None were found. Hill was taken to Hartford Hospital by LifeStar helicopter for evaluation. The Marlborough Fire Department extinguished a small fire that resulted from the explosion.

Investigators determined that Hill and several other teens were watching a bonfire when someone placed an unknown object in a plastic bag into the fire. The object exploded, resulting in fragments striking and injuring Hill.

Detectives from the Eastern District Major Crime Squad and the Fire and Explosion Investigation Unit assisted with the investigation.