Serial killer Tsutomu Miyazaki, 45, who abducted, molested and strangled four young girls in Tokyo and Saitama Prefecture in 1988 and 1989, was hanged Tuesday along with two other inmates, Justice Minister Kunio Hatoyama said.

Hatoyama has now signed 13 execution orders since taking his post in August, the highest by a single minister since executions resumed in 1993.

"In all three cases, the inmates committed cruel acts for very selfish reasons," Hatoyama told reporters. "I ordered the executions to protect the rule of law."