TOKYO, Dec 25 (Reuters) Japan hanged four convicts today in its first executions in more than a year, the Justice Ministry said, prompting protests from lawmakers and human rights groups.

As usual, the ministry did not identify the four, but media reports said those executed on Christmas Day included Hiroaki Hidaka, 44, who had been convicted of killing four women including a 16-year-old girl. Under Japan's capital punishment system, inmates and their relatives are not told of an impending execution until the day it takes place, a practice many say is inhumane.

Japan often carries out executions several times a year, usually when parliament is not in session or in December, when the country is winding down for the New Year holidays, in what critics say is a strategy to avoid discussion of the issue in parliament.

Seiken Sugiura, the predecessor of the current Justice Minister, caused a media fuss by saying on his appointment in 2005 that he would not sign death warrants.

He later withdrew the remarks, but no executions took place while he was in office. The previous execution took place on September.

16, 2005, when one convict was hanged.

''The death penalty is cruel, ruthless and entirely undemocratic,'' a cross-party group of lawmakers opposed to the death penalty said in a statement.

''It has no effect in controlling crime and instead breaks down society's morals,'' said the group, which is headed by Shizuka Kamei, a conservative lawmaker and former police officer.

Amnesty International Japan also issued a statement calling for Japan to abolish the death penalty, saying that 88 nations, including most developed countries, have already done so.

But capital punishment is little questioned by most Japanese, who are shown by polls to support the death penalty in the face of a recent rise in violent crime.

REUTERS DKA PM1406