At least seven people – three bystanders and four firemen – fainted on Monday due to an ammonia leak in an ice factory in Meanchey district, leading authorities to arrest the factory owner and evacuate workers, law enforcement said.

Meanchey district deputy police chief Huor Meng Vang said the leakage was caused by a careless welder who repaired a factory pipe. “The welder fused the old pipe while the gas was running, and the explosion created a lot of holes in the pipe,” Van said.

Both the factory owner and the welder were brought in for interrogation, and the case will be sent to court, he added.

Prom Yorn, director of the Phnom Penh Municipal Fire Department, said the situation was difficult for fire fighters to remedy because the ammonia continued to cause shortness of breath and fainting.

“It’s difficult because the gas spreads out and it is hard to contain,” Yorn said. “We cannot control it, because the holes are big.”It took four hours to get the situation under control, he added.