About 1 kg of potassium cyanide disappeared sometime between Saturday afternoon and Sunday morning from the warehouse of a company in Tokyo that deals in deadly substances with industrial uses, police said.

Police said an employee of Uemura Shoten found about 1 kg of potassium cyanide -- enough to kill several thousand people -- missing from a 20-kg container in the warehouse at around 6:50 a.m.

Uemura Shoten in Tokyo's Kita Ward is a small company with only a handful of employees. Nobody was watching the warehouse between 12:30 p.m. Saturday and Sunday morning, and the firm believes the chemical was stolen during that period.

The warehouse was locked, but several windowpanes in a nearby office were found broken and missing their iron grates, police said.

Potassium cyanide is a deadly, white, crystalline compound used in electroplating and insecticide. yyye