Puffer fish or blowfish
In a picture taken on June 5, 2012, a pufferfish, known as fugu in Japan, is seen on a chopping board to remove toxic internal organs at a Japanese restaurant 'Torafugu-tei' in Tokyo.YOSHIKAZU TSUNO/AFP/GettyImages

A warning has been issued in a Japanese city through emergency loudspeaker system to alert residents against consuming the blowfish or puffer fish after potentially poisonous parts were mistakenly sold.

Also Read: This Mexican fish's mating call is so loud that it can deafen sea lions and dolphins

Regional health officials said that a supermarket in Gamagori in central Japan sold at least five packages of fugu fish without taking out the deadly liver. The officials have located three packages, but two are still missing, local official Koji Takayanagi told AFP.

Also Read: Is it a zombie fish? This viral video of a cooked fish rising from the dead may horrify you

"We are calling for residents to avoid eating fugu, using Gamagori city's emergency wireless system," he told AFP. "Three packages will be retrieved today, but we still don't know where the remaining two are."

The officials are using loudspeakers, which are used to make announcements during an earthquake and other disasters, to alert residents.

"Eating a blowfish liver can paralyse motor nerves, and in a serious case cause respiratory arrest leading to death," regional officials said in a warning statement.

Fugu fish or puffer fish is Japan's one of the most expensive winter delicacies, but it can turn deadly if not eaten with caution. The fish's skin, ovaries and livers contain tetrodotoxin poison, which is described as "rapid and violent." Tetrodotoxin poison will cause numbness around the mouth, then paralysis and that can lead to a person's death. And there is no antidote to this poison.

Chefs in Japan are required to obtain a special license for preparing the fish. They even have to undergo training to obtain the license.

Several people in the country are killed each year because of the incorrect way or rashly trying to cook the fish. But people in Japan have eaten this fish for centuries now.

"In Japan, we were eating fugu 8,000 years ago, and many people died because of the poison," chef Masato Sawahara said, as quoted by Prestige. "But we've continued to eat it, because the Japanese people savour the real taste of fugu."