TOKYO, Japan (AP) — A grandson of ex-US President Harry Truman, who ordered the atomic bombings of Japan during World War II, is in Hiroshima to attend a memorial service for the victims.

Clifton Truman Daniel visited the Hiroshima Peace Memorial Park yesterday and laid a wreath for the 140,000 people killed by the August 6, 1945, bombing authorised by his grandfather. Another atomic blast in Nagasaki three days later killed 70,000 more.

"I think this cenotaph says it all — to honour the dead to not forget and to make sure that we never let this happen again," Daniel said after offering a silent prayer.

Daniel is in Japan to attend ceremonies this week in Hiroshima and Nagasaki marking the 67th anniversary of the bombings. His visit, the first by a member of the Truman family, is sponsored by the peace group Sadako Legacy, named after Sadako Sasaki, an A-bomb victim who died of leukemia at age 12. While in the hospital, Sadako folded hundreds of paper cranes after hearing a legend that people who make 1,000 origami cranes can be granted a wish. Origami cranes have since become a symbol of peace.

Daniel met Sadako's 71-year-old brother, Masahiro Sasaki, who survived the bombing, at a peace event in New York in 2010. They agreed to work together to deepen understanding between the two countries, which are still divided over the question of the legitimacy of the atomic attacks.

Daniel said in a statement that he decided to visit Hiroshima and Nagasaki because he needed to know the consequences of his grandfather's decision as part of his own efforts to help achieve a nuclear-free world. He said he hoped to hear stories from survivors about how they overcame their adversity.

Daniel also is to meet with the mayors of Hiroshima and Nagasaki and participate in discussions with students.

The peace group also invited the grandson of a radar operator who was on both of the planes that dropped the atomic bombs.

Ari Beser's grandfather, Jacob Beser, was the only person who directly took part in both the Hiroshima and Nagasaki bombings.

"I hope we can bring a true reconciliation to atomic bombing survivors, many of them still caught in animosity toward the United States, as well as other survivors of war and their families, and help instil a strong sense of peace among young people," Sasaki said in a statement.