A 12-year-old boy ended up with a perforated stomach after gulping down a liquid nitrogen-chilled treat at a water park in central South Korea, medical sources said Thursday.

The boy finished the cupful of puffy cereal soaked in nitrogen bought from an eatery at the water park in Cheonan, a city in the central province of North Chungcheong, on Tuesday. The dessert, called Dragon's Breath, makes the people who eat it exhale smoky nitrogen vapor.

His father, who visited the resort with him, rushed his son to a general hospital in the city where doctors found a 5-centimeter-wide hole in his stomach and took him to surgery before placing him under intensive care. He has been transferred to a general ward.

The hospital's medical staff believe that he may have drank liquid nitrogen when he downed the last mouthful of the treat.

Nitrogen with a temperature of 200 C below zero is injected into this kind of treat. The boy is believed to have consumed residual liquefied nitrogen on the bottom of the cup after some nitrogen appeared to have melted, they said.

Drinking liquefied nitrogen can deal lethal damage to people's internal organs.

A health official at the city's Southeastern Ward office said it has asked police to investigate the case following the tipoff from the boy's family.

The police summoned an employee of the eatery on suspicion of professional negligence resulting in injury after the boy's parents filed a complaint over the incident.

The eatery, which is now closed, had been operating without a business license, they said. (Yonhap)