Human rights watchdog Amnesty International has urged Saudi King Abdullah to commute amputation sentences handed down against six men convicted of highway robbery in the ultra-conservative Muslim kingdom. The sentences to chop off the right hands and left feet of the six Saudis is currently before the Supreme Court for approval and could be carried out within days if ratified by the king, the London-based group said on Friday. It said they were forced to confess. ''Cross amputation' is a strikingly cruel form of punishment that amounts to torture and should have no place in a criminal justice system,' said the watchdog's Middle East and North Africa interim director, Philip Luther. 'We are urging the king to use his authority to urgently commute these sentences and spare these men this horrific punishment,' he added. Amnesty said the men are Barzan bin Raheel al-Shammari, 29; Amer bin Eid al-Jarbaa, 26; Mohammad bin Ali al-Shammari, 25; Mohammad bin Dhiyab Maddhi, 27; Abdullah bin Dhiyab Maddhi, 30; and Bandar bin Abbas al-Asadi, 22. The bedouin men were arrested in October 2010 in Riyadh, accused of 'highway robbery' and taken to Malaz prison in the capital. All were allegedly beaten and forced to confess to the charges against them, Amnesty said. Jarbaa was reportedly beaten for eight days and told that if he did not confess, his three brothers would be arrested. 'It appears that he signed a confession without knowing its contents and was later held in solitary confinement for 33 days,' it charged. The men were tried before the General Court in Riyadh with no legal representation and were sentenced in March 2011 to 'cross amputation', it said, adding that an appeal court upheld the sentences in October. Saudi Arabia enforces amputation of the right hand as a punishment for theft, while cross amputation is imposed in cases of highway robbery, Amnesty said. Armed robbery can be punishable by execution in the desert kingdom. Rape, murder, apostasy and drug trafficking also carry the death penalty under Saudi Arabia's strict interpretation of Islamic sharia law.