Japan executed two death-row inmates Tuesday, bringing the total number of prisoners hanged this year to 15, a news report said.

The hangings, reported by Kyodo News agency, were the first since three inmates were executed in mid-September.

Japan in recent years has increased the pace of its executions, which are not announced beforehand and are carried out in secret. Nine inmates were executed in 2007.

The two hanged on Tuesday were Michitoshi Kuma, 70, and Masahiro Takashio, 55, Kyodo reported, citing the Justice Ministry. The report did not detail their crimes.

The stepped-up pace of executions over the past few years have brought strong protests from advocacy groups such as Amnesty International, though capital punishment has public support in Japan.

There are about 100 people on death row in Japan.