An annual Buddhist rite for "muen botoke" -- people who died and left behind no known relatives -- was held Friday at a temple in eastern Tokyo, a grim reminder of the soaring number of remains in recent years that are buried under these circumstances.

Genjuin Temple in Katsushika Ward has been accepting the cremated remains of people whose identity is unknown or those of people who have died leaving no kin.

This year's rite was performed for more than 400 sets of remains kept in urns that the temple accepted during 2001.

After the rite, the ashes, which are kept at the temple for at least a year in case relatives show up to retrieve them, were buried together beneath a memorial tower in the temple's compound.

The number of muen botoke accepted each year has more than tripled from a decade ago, possibly due to the nation's protracted economic slump and other social changes, said Tatsuaki Ono, chief priest at the temple.

"The increase in muen botoke can be explained by the soaring homeless ranks, who usually die leaving no (known) relatives," Ono said. "It also symbolizes the diminishing traditional kinship in Japan."

The temple has voluntarily accepted more than 5,000 muen botoke urns from ward offices across Tokyo since 1969.