People in Tokyo have observed the 78th anniversary of a devastating US air raid on the Japanese capital during World War Two.

Some 100,000 people died in the predawn attack by B29 bombers on the eastern residential areas of Tokyo on March 10, 1945.

About 100 people attended a service held at a memorial hall in Tokyo's Sumida Ward on Friday. They included Crown Prince and Princess Akishino and Tokyo Governor Koike Yuriko, as well as victims' families.

A 79-year-old woman said she lost three family members in the air raid. She said people kill each other in war and she hopes for a war-free world where everyone can live peacefully.

A 60-year-old man said he lost his grandparents in the attack. He said he did not experience the war but he thinks he owes his peaceful life to those who sacrificed themselves in it. He said he wants to pass this down to the next generation.