Almost two dozen Marines were injured on Feb. 12 after a fire extinguishing system malfunctioned aboard a vehicle during a training exercise in a California base. Though the Marines were not seriously injured, they were transported to nearby hospitals for treatment.

The U.S. Marine Corps released a statement explaining 22 Marines were injured when a fire extinguishing system aboard an Assault Amphibious Vehicle "inadvertently malfunctioned."

The training exercise took place at the Marine Corps Air Ground Combat Center, Twentynine Palms, California, and it involved Marines and sailors from the 2nd Battalion, 3rd Marine Regimen. They participated in the Integrated Training Exercise 2-15.

The Associated Press reports the equipment malfunctioned and released the fire extinguishing contents within the armored vehicle. Though there was no explosion or fire, the Marines were exposed to halon, a chemical used to extinguish fires.

Base spokesman Dave Marks said the injured Marines were taken to the base hospital, and only three were kept overnight for observation; the rest were released.

Though it was banned to manufacture back in 1990s for it depletes the ozone, the use of halon is still allowed as it is non-toxic and leaves no residue, but in high concentrations it can cause breathing problems.

The Twentynine Palms base, some 130 miles east of Los Angeles in southern California, is the biggest Marine training base in the world.

"Ninety percent of the Marines will cycle through here for their combined-arms training," Marks said.

Though the vehicle involved has not been identified, it is likely it is the AAV-7, the Marine's amphibious assault vehicle first deployed during beach raids, according to the Marine Corps. website. The vehicle can also carry 21 Marines and 3 crewmembers, a large enough capacity to carry the 22 injured Marines.