'Two thirds of the known executions of child offenders in the past decade were carried out in the USA', the organisation said. 'It is clear that the United States is the world's leading perpetrator of this universally condemned human rights violation.'

In his recent speech on Iraq to the UN General Assembly, President George Bush spoke of 'broken treaties', UN resolutions being 'unilaterally subverted', and of the USA's wish for the UN to be 'effective, and respected, and successful'.

'The execution of child offenders leaves treaties just as broken, resolutions just as subverted, and respect for the UN and international law just as undermined,' Amnesty International said.

One of the two Amnesty International reports focusses specifically on the USA. It was prompted by the recent US Supreme Court decision that the execution of people with mental retardation violates the constitutional ban on 'cruel and unusual' punishment. In Atkins v Virginia, the Court concluded that US 'standards of decency' had evolved to the point that there was a 'national consensus' against such executions.

'Applying the Supreme Court's reasoning in the Atkins case to the execution of child offenders leads to the conclusion that such use of the death penalty is unconstitutional too,' Amnesty International continued. In its report the organisation points out that, in some respects, the evidence of a 'consensus' against the judicial killing of child offenders is stronger than that existing against the execution of the mentally impaired.

'The Supreme Court sees state legislation as the primary indicator of consensus,' Amnesty International pointed out. 'Yet for all but a tiny fraction of the past 25 years, the number of states prohibiting the execution of child offenders has been greater than in the case of people with mental retardation.' The organisation's report suggests that public hysteria in the 1990s about youth crime may explain the relative slowdown in legislative progress on the juvenile death penalty issue.

'What is more, states have executed about twice as many people with mental retardation as they have child offenders', Amnesty International continued, adding that while there are about 80 child offenders on death row, the figure in the case of the mentally retarded was estimated to be around 200 to 300 people at the time of the Atkins decision.

'This would suggest that the death penalty against child offenders has been the more 'unusual' of the two practices', Amnesty International said. 'It is no less cruel'.

'In the Atkins case, the Supreme Court found that the traits of people with mental retardation render the goals of deterrence and retribution unachievable,' Amnesty International said. 'Characteristics of Children's rights, such as impulsiveness, poor judgment, and susceptibility to peer pressure or adult influence, surely lead to the same conclusion. Indeed, scientific evidence indicates that brain development continues into a person's 20s.'

The immaturity of teenagers is widely recognised in US laws. Under-18s cannot serve on a jury, yet can be condemned by those considered responsible enough to sit on one. In Louisiana, under-18s are prohibited from witnessing an execution, yet seven people currently await execution there for crimes committed when they were 16 or 17.

In the Atkins ruling, the Supreme Court acknowledged that 'within the world community' the execution of the mentally retarded is 'overwhelmingly disapproved'. The disapproval is even clearer in the case of child offenders. Such executions are prohibited by several treaties and have been the subject of numerous resolutions at the UN Commission on Human Rights.

Since January 1993, Amnesty International has documented 24 executions of child offenders worldwide - one in Democratic Republic of Congo, one in Nigeria, one in Yemen, two in Pakistan, three in Iran, and 16 in the United States. Pakistan and Yemen have since legislated to abolish such use of the death penalty, as did the world's main executing country, China, in 1997.

The USA reserved the right to execute child offenders when it ratified the International Covenant on Civil and Political Rights, even though that treaty contains a non-derogable prohibition on such executions. The relevant expert UN body has found the US 'reservation' to be invalid, but the US has ignored its finding. UN bodies have also affirmed that the prohibition has become a principle of customary international law, binding on all countries regardless of which treaties they have or have not ratified.

'Perhaps this issue provides the starkest example of how far the USA is from the progressive force for human rights it so often claims to be,' Amnesty International concluded. Since 1990, 191 countries have ratified the Convention on the Rights of the Child, one of the treaties banning the use of the death penalty against Children's rights who were under 18 years old at the time of the crime. Only Somalia and the USA have failed to ratify.

Read Amnesty International's two new reports:

- Indecent and internationally illegal, the execution of child offenders in the USA - full version

- Indecent and internationally illegal, the execution of child offenders in the USA - abridged version. (The full report includes tables and footnotes.)

- Children's rights and the death penalty: Executions worldwide since 1990 /p>