Three prisoners on death row in Japan have been hanged, the country's justice ministry has said.
The executions bring to 10 the number of prisoners hanged since December 2006.
Officials did not reveal the identities of the executed prisoners, but a human rights watchdog said that they were men in their 60s convicted of murder.
Japan, like the United States, is one of the world's few developed countries to exercise capital punishment.
Before December 2006, there had been a 15-month halt in executions because then Justice Minister Seiken Sugiura opposed the death penalty.
But since his replacement by Jinen Nagase, seven men have been executed, four in December and three in April.
Human rights watchdog Amnesty International and media reports identified the men as Hifumi Takezawa, 69, and Yoshio Iwamoto, 60, who were executed in Tokyo, and Kozo Segawa, 63, who was executed in Nagoya.
One hundred and four inmates are currently believed to be on death row in Japan, the Associate Press news agency says.
Japan has faced international criticism for the secrecy that surrounds the executions.
Inmates are given little notice that they will be executed, so as to prevent last-minute appeals.
Critics have also noted that Japan conducts executions while parliament is in recess, allegedly to avoid debate on the topic.