BEIJING (AP) _ China on Thursday rejected U.N. criticism of its strict limits on union organizing and denied that labor activists have been jailed for advocating independent unions.

Chinese labor minister Zhang Zuoji said the Communist Party's monopoly on unions is suited to China and will stand for no outside criticism.

``We cannot accept the prejudices that some international organizations and some individuals hold against China and their practices over these issues,'' Zhang said after signing a cooperation agreement with Somavia.

Earlier, Juan Somavia, director general of the U.N. International Labor Organization, passed Zhang a list of 24 people the ILO says have been detained in China for attempting to set up independent workers' groups or participating in legitimate trade union activities. The ILO asked that they be released.

``No worker should be imprisoned or penalized for carrying out legitimate trade union activities,'' said Somavia, who is visiting Beijing.

Zhang said Chinese investigations into those cases determined that all were convicted on criminal charges ``unrelated to the issue of free association.''

ILO officials said they were told the 24 were found guilty of charges ranging from hooliganism to violating vague state security laws and have been in jail for up to eight years.

China has not ratified the ILO's convention on forming independent unions.

Beijing allows only one national trade union controlled by the ruling Communist Party. Authorities have arrested or forcefully committed to mental hospitals activists who tried to form or called for free trade unions or who pushed for workers' rights.

With millions of people laid off from failing state industries, the government has struggled to contain worker resentment. Protests over unpaid wages, lost pensions and stolen assets have become commonplace.

Somavia also criticized China's system of labor camps to punish less severe crimes, saying they were a form of forced labor. Chinese police can send people to labor camps for up to three years without trial.

Zhang said Somavia was confusing forced labor and criminal justice. The labor camp system has proven effective for reforming minor criminals, he said.