CNN  — 

Employees of the fireworks company behind the July 4th celebration in Ocean City, Maryland, received minor injuries Sunday after the fireworks accidentally exploded.

First responders initially thought a car was on fire, but when they arrived at the scene they discovered there was “an unintentional discharge of fireworks” being set up for the show, the Ocean City Fire Department said in a Facebook post Sunday morning.

The employees declined transport to a local hospital, and no other beach or boardwalk visitors were injured as a result of the explosion, the fire department said.

“Prior to the fireworks being off-loaded from the vehicle, Fire Marshals secure a safe zone around the fireworks and put other safety protocols in place,” Ocean City Fire Chief Richie Bowers said in the statement. “It is this very zone and safety protocols that kept anyone else from being injured.”

View of the fireworks from the boardwalk.

A spokesperson for Starfire Corporation, the company responsible for administering the fireworks display in Ocean City, told CNN they are investigating the cause of Sunday’s explosion along with several other agencies.

All the products used in the fireworks display were shipped from overseas locations, the spokesperson said, adding that the fireworks and shipment origins are also being looked into.

“Starfire Corporation feels terrible about what happened, and we are grateful to the Ocean City Fire Department and all the other agencies that helped today,” the spokesperson told CNN.

Everyone in the crew managing the fireworks were well trained, licensed and were following protocols when administering the fireworks display, they said.

Fire marshals are on scene and continue their investigation into the fireworks discharge.

All fireworks celebrations in Ocean City have been canceled out of “an abundance of caution,” the Ocean City Fire Department confirmed on Facebook.

“At this time, the cause of the fireworks discharge is unknown,” the fire department said. “A perimeter around the fireworks site has been established and will remain in place until the safety inspections are complete, which could take several days.”

Areas of the boardwalk will also remain closed to pedestrians until safety inspections have been completed.

The downtown show was supposed to begin with musical guests at 8 p.m. EST, with crowds expecting to see “fireworks filling the sky” beginning 9:30 p.m., according to a press release. The Northside Park was expected to take place at 8 p.m. EST, with a fireworks display at 9:30 p.m.

CNN’s Ganesh Setty contributed to this report.