The organisation issued an international Urgent Action appeal on 27 February naming five men believed to be "at imminent risk of execution".
It said the minister wanted to increase the pace of executions, and he "is seeking to avoid public objections by singling out for execution those who, like these five, have recently abandoned their appeals or were convicted of crimes that have led to 'public revulsion'."
The men are:
- YAMAJI Yukio (m), born 1983
- SHINOZAWA Kazuo (m), born 1952
- ZODA Hiroshi (m), born 1976
- MAEUE Hiroshi (m), born 1971
- OGATA Hideki (m), born 1980.
Mori Eisuke has now sent six men to the gallows since he was appointed justice minister on 24 September 2008.
The last executions were carried out on 29 January 2009, when four men were hanged for murder.
Younger, faster death
Unusually for Japan's death penalty system, four of the men named are under 40 years of age.
Death row prisoners often wait several decades in prison before they are executed, usually receiving only a few hours' notice of when they will be killed. Some receive no warning at all.
However there have been recent worrying signs that Japan is speeding up executions after sentences are finalised.
Of the 32 people hanged in Japan since December 2006, five were aged in their 70s and 12 were in their 60s.
Japan: New year, more hangings -- 29 January 2009
Japan may execute before year ends -- 16 December 2008
Japan: Record toll with new hangings -- 28 October 2008
Japan: New minister faces next hanging -- 14 October 2008
Japan: New minister sends three to death -- 12 September 2008
Japan: Minister steps up rate of hangings -- 12 April 2008
Long wait, sudden death in Japan -- 28 August 2006
[Corrected 9 March 2009, updated information issued by AI.]