Mishal Husain: "Human rights organisations striking a cautious note"

Mrs Robinson, the first UN Human Rights Commissioner allowed into China, has received an open letter from the dissidents in which they describe the system as "savage" and a violation of human rights.

Under the punishment, known as "re-education through labour", suspected criminals and dissidents can be imprisoned for three years.

Mrs Robinson is due to meet China's President Jiang Zemin and Deputy Prime Minister, Qian Qichen, during her 10-day tour, which includes a visit to Tibet.

Beijing has never before allowed a UN delegation into Tibet, which it annexed in 1950.

Asked how she would judge the success of the visit, Mrs Robinson said she hoped to reach a memorandum of intent with China on future human rights work that would build on momentum from her trip.

Beijing's handling of the Tiananmen Square protests is still criticised by the west

"I am very keen to ensure that the memorandum of intent is already one that has practical implications," the former Irish president said on arrival in Beijing.

It is however not yet clear whether she will meet pro-democracy activists.

More than 50 Chinese dissidents have requested a meeting to discuss their plight, and the wife of China's most prominent dissident, Liu Nian Chun, has appealed to Mrs Robinson to help secure his release from prison for medical treatment.

'Gradual process'

A UN human rights spokesman said the subject of meetings with dissidents was very delicate for reasons of their own protection.

Mrs Robinson stressed her trip was a beginning in a gradual process of fostering better human rights in China. She hopes to secure guarantees from Beijing that it will fulfil pledges to sign a covenant on civil and political rights in the next few months.

The issue of human rights has long been a sticking point in China's relations with the west, with Beijing dismissing criticism of its human rights record as interference in its internal affairs. China has been criticised in particular for a long history of alleged rights abuses in Tibet.