Unexploded commercial-grade fireworks shells washed up on Chappaquiddick Island after the Fourth of July, as public safety officials urge anyone who sees similar devices to call 911.

Massachusetts fire officials are blaming Central Maine Pyrotechnics, accusing the fireworks company of improperly disposing the two dozen highly hazardous fireworks shells after a show.

“The Office of the State Fire Marshal today issued immediate threat suspensions to Central Maine Pyrotechnics and the individual who conducted the display, prohibiting them from conducting fireworks displays pending a hearing on July 26,” the Massachusetts Department of Fire Services said in a statement on Thursday.

But the head of Central Maine Pyrotechnics told the Herald that the allegations are “completely false,” saying the fireworks shells didn’t light like they were supposed to before falling into the ocean.

“Nothing was disposed of improperly,” said Steven Marson, president and owner of Central Maine Pyrotechnics.

“The shells were fired, and they didn’t explode in the air like they were supposed to, and fell back in the ocean,” he added.

Members of the Massachusetts State Police Bomb Squad responded to Chappaquiddick Island on Wednesday after 25 unexploded shells were found washed up on the beach.

Along with help from the Edgartown Fire Department, bomb technicians recovered the fireworks shells and transported them to a safe location before countercharging the devices.

All of the known shells have been cleared from the beach, but there’s a chance that more shells may wash up, officials warned.

“In the event that you come across an unfamiliar object resembling the ones depicted in the accompanying photo, it is crucial to immediately contact emergency services at 9-1-1,” the Massachusetts Department of Fire Services said in a statement. “This prompt action will ensure that trained professionals can promptly and safely handle the proper disposal of the object.”