China is running a number of unlawful detentioncentres in which its citizens can be kept for months, according to Human Rights Watch.人权观察组织称，中国境内存在一定数量的非法拘留点，市民可能在这里被囚禁长达数月之久。
Former inmates claim they were beaten and raped in the jails
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.
'Punched and kicked'
The human rights group report, entitled An Alleyway（小巷，窄街） in Hell, says ordinary people are often abducted（诱拐，绑走） off the streets and taken to illegal detention centres.
They 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.
"I asked why they were detaining me, and as a group [the guards] came in and punched and kicked me and said they wanted to kill me," one former detainee told the group.
"I loudly cried for help and they stopped, but from then on, I didn't dare [risk another beating]."
Many of those held are petitioners（请愿人）, people who travel to Beijing to present their complaints to the State Bureau for Letters and Calls.
This national government department is supposed to help ordinary people across the country redress their grievances（委屈，冤情）.
But some petitioners are detained by plainclothes security officers when they arrive in Beijing.
"The existence of black jails in the heart of Beijing makes a mockery（嘲弄，笑柄） of the Chinese government's rhetoric（修辞） on improving human rights and respecting the rule of law," said Sophie Richardson, Asia advocacy director at Human Rights Watch.
Outcry over deaths
China regular denies such claims, but even state-run media outlets have reported the existence of black jails.
The China Daily last week carried a report about the trial of a black jail guard accused of raping a 20-year-old woman who had been detained.
Black jails are just one aspect of China's detention system that have come in for criticism over recent months.
There has been a public outcry（尖叫，倒彩） over the numbers of deaths in prisons and detention centres, a situation the government has promised to stamp out（踩灭，消灭）.
