By DPA
Tokyo : Four inmates were executed Thursday in Japan, Justice Minister Kunio Hatoyama said, bringing the number of death penalties carried out there since December to 10.
The convicted murderers, aged 41 to 64, were hanged at prisons in Tokyo and Osaka, Hatoyama said.
The series of multiple executions over the past four months has been the biggest cluster to be carried out since Japan resumed executions in 1993.
The reason for the increase has been a rise in the number of death sentences, Japanese media reported.
Hatoyama, who must personally approve each execution, said he was only carrying out his duty.
He had paid attention to the interval between executions as little as he had the number of condemned men and would continue to do so, Hatoyama was quoted as saying by the Jiji Press news agency.
The human rights group Amnesty International criticised the executions, noting that executions in Japan were picking up amid a worldwide trend toward the abolition of the death penalty.
Japan, where another 104 prisoners sit on death row, is one of the few industrialised countries that still carry out executions.
Human rights organizations have criticised the practice and the secrecy surrounding the death penalty in Japan for years. Relatives only learn of the executions after they are carried out, and the inmates themselves are informed the morning of the executions, a few hours before their deaths.