The Human Rights Watch say China is running a number of unlawful detention centres in which its citizens can be kept for months. It says these centres known as black jails are often in state-run hotels, nursing homes or psychiatric hospitals.Among those detained are ordinary people who have travelled to Beijing to report local injustices.China says it is a country ruled by laws, but there are other sources to suggest that black jails do exist.The human rights group report, entitled An Alleyway in Hell, says ordinary people are sometimes stripped of their possessions, beaten and given no information about why they have been detained.Human Rights Watch said it collected information for the report by interviewing 38 detainees earlier this year.