Shozo Tominaga, a peace activist who had been interned as a war criminal in China after World War II, died Sunday of heart failure at a hospital in Yokohama, his family said Monday. He was 87.

Tominaga was known for his outspoken opinion that Japan should never again engage in war. He founded a peace activist group in 1957 with former Imperial Japanese Army soldiers who had also been detained in China.

Tominaga iterated at meetings that Japan must admit its culpability for past wars and stressed that people should not allow the state's involvement in invasions of foreign countries.