A violent blast of fireworks accidentally set off by workers on a Maryland beach Sunday sent terrified sunbathers fleeing amid huge plumes of smoke, video shows.

The premature detonation occurred in Ocean City just after 11 a.m. as employees of a fireworks company were preparing for the city’s annual evening July Fourth display, authorities said.

At least some workers suffered minor injuries, although they declined to go to the hospital, the Ocean City Fire Department said in a statement on Facebook. 

No one on the beach or boardwalk was hurt in the debacle, some of which was captured on video by CBS-TV affiliate WUSA.

The local fire department had responded to the scene thinking a car had caught fire, only to find it was botched fireworks, officials said.

“Our Fire Marshals are on the scene and will investigate the cause of the unintentional discharge,” said Fire Chief Richie Bowers in the statement.

More people could have been injured had the department not established a “safe zone” around the launch area earlier in the day, the fire chief 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.  It is this very zone and safety protocols that kept anyone else from being injured,” Bowers said.

The fireworks display had been scheduled for 9:30 p.m. as part of the city’s annual Fourth of July festivities. They have since been canceled “out of an abundance of caution,” the fire department said.