Juliet Hindell: "Nowhere and nothing seems totally safe"

The situation has been made worse by the fact that none of the crimes have been solved.

The arsenic-laced curry was deadly

The poisonings started when four people died and 60 people were taken to hospital after eating arsenic-laced curry at a community festival near the city of Osaka.

Following the incident in July there have been a series of poisonings.

In August, a man collapsed and died within hours of drinking a can of tea laced with cyanide from a supermarket.

Poisoned tea and other contaminated vending machine drinks have also sent dozens of people to hospital.

Copycat poisonings

The Japanese media has reported that the curry murder case may have been part of a macabre life insurance plan, but as yet no arrests have been made.

Police who are struggling to solve the series of crimes are calling the poisonings copycat incidents.

The BBC's correspondent in Tokyo, Juliet Hindell, says that the people of Japan have not felt so vulnerable since a doomsday cult released poison gas on trains in Tokyo three years ago.

Some people believe the poisonings reflect a weakness in Japanese society.

Yuko Kawanishi: Society is partly to blame

"I think Japanese people have a tendency to be more easily swayed or influenced by a mood or social atmosphere," said university professor Yuko Kawanishi. "People's emotions can easily transmit to others."

One frightened man blamed the poisonings on a decline of Japanese morals. But another passed off the incident as a fad, saying "things like this happen every year".