At least four people killed themselves April 25 by inhaling fumes from detergent mixed with other chemicals as a wave of similar suicides grew in Japan, reportedly claiming more than 50 lives in April.

Authorities are alarmed by the sudden rise in such incidents — an average of two a day were reported in April — because the chemicals are easy to get and the fumes could spread to sicken bystanders or rescuers.

The government has been battling to contain the country's alarmingly high suicide rate. The government said 32,155 people killed themselves in 2006, giving Japan the world's ninth-highest suicide rate.