Japan has long battled a high suicide rate, and is now in the grip of a wave of deaths from mixing commonly available household products to form poisonous hydrogen sulfide gas. The gas can form noxious clouds that also affect those who happen to be nearby, often triggering mass evacuations.

The number of toxic fume suicides jumped to 876 from January to September compared to 29 last year, the Cabinet Office said.

Alarmed by the surge, police have launched a crackdown on popular Internet sites that give instructions on how to commit suicide using the method.

Toxic fume suicides are the latest in a series of suicide fads in Japan. Until this year, many suicide cases involved people who found each other on the Internet and committed suicide together, often by sealing themselves in a car and lighting a charcoal-burning brazier.

The number of suicides hit 33,093 in 2007, a 2.9 percent increase from the previous year and the second-highest annual tally on record, according to the National Police Agency.

To curb the nation’s high suicide rate, the government has earmarked $220 million for anti-suicide programs to help those with depression and other mental health problems.

Japan has the eighth highest suicide rate in the world, according to the World Health Organization.