About 150 Japanese and Americans gathered in Kisarazu, Chiba Prefecture, on Tuesday for a memorial service honoring 12 U.S. airmen who died when their B-29 bomber was shot down during World War II.

The service followed the discovery a few years ago of a monument built in memory of the crew in the mountains of Kisarazu. The 80-cm stone was erected in 1951 by Kinji Kageyama, a farmer who lived near the bomber's crash site and died in 1983.

For decades, few besides Kageyama's family knew about the marker, but after local residents found the slab with an inscription that reads "tomb of B-29 crew," they wanted to hold a memorial service for the dead.

The bomber was part of a raid on Yokohama in May 1945 when it was shot down.

"My father must have been affected by the crash as if it had been his own, because he had lost his father and younger brother in war," said Kageyama's second son, Junichi, 61. "I'm delighted that a lot of people have learned about the feelings of my father, who entombed the victims with care, whether they were allies or enemies."