Keiji Nakazawa, a Hiroshima atomic bomb survivor whose iconic comic strip about the incident was read by millions of school children in post-war Japan, has died, associates said Tuesday.

Nakazawa, who had been ill with lung cancer, passed away last week at a hospital in Hiroshima at the age of 73, surrounded by family, according to his longtime friend Koichiro Maeda, head of the Hiroshima Peace Memorial Museum.

The author's "Barefoot Gen" manga series, which carried strong anti-war themes and often gruesome drawings, was serialised in magazines from 1973 to 1985 and was also turned into books that sold more than 10 million copies, according to Japanese media.

The series focused on a character named Gen Nakaoka and depicted how he survived the blast and lived through tumultuous post-war years.

It has been translated into 18 languages, including English, French, Korean, Thai, Russian and a few Scandinavian languages.

"I met him in October and talked about the 40th anniversary of Barefoot Gen next year. He looked spirited, if not perfect, although he had been in and out of hospital," Maeda told AFP by telephone on Tuesday.

Nakazawa made his debut as a comic artist in 1963 but refused to write about his A-bomb experiences until 1966 when his mother died of what was suspected to be the after effects of radiation.

He did not attend the annual Hiroshima anniversary ceremonies until last year, saying: "I want to convey my anger toward atomic bombs and my thoughts on the war to future generations."

Nakazawa was just six years old and on his way to school when the blast struck on August 6, 1945 in the final chapter of World War II.

His father, older sister and younger brother died while Nakazawa's mother and older brother survived the blast.

An estimated 140,000 people died instantly in the massive explosion or from radiation in the days and months after a US bomber unleashed the deadliest weapon ever seen at the time, ushering in the nuclear age.

Over 70,000 perished as a result of another US atomic attack on the port of Nagasaki three days later.