Kigali - Members of Rwanda's security forces are arresting beggars, street children, sex workers and other "undesirables" who are arbitrarily detained in centres described as harsh and inhuman, Human Rights Watch said on Thursday.Its new report raises questions about the central African country that is often praised by the international community for its organised appearance but challenged by rights groups amid concerns over authoritarian actions.Human Rights Watch said it had received information about several people who died during or just after their detention in a "transit centre" in Rubavu in Western Province as a result of injuries from beatings, poor conditions and lack of medical care.Rwandan police and other security groups round up poor people as part of an unofficial government practice to remove "undesirables" from the streets of the capital, Kigali, and other urban areas, the new report said.It said some people are held for weeks or even months in what are also called "rehabilitation centres."Rwandan Justice Minister Johnson Busingye told Human Rights Watch the matter will be investigated.Damas Mutagomwa, a justice ministry official, said torture is punishable under the law and police officers who torture detainees will be prosecuted. He said Human Rights Watch researchers interviewed alleged victims anonymously, making it hard to follow up.The rights group looked into four centres out of at least 28 across the country. It urged the government to close the centres and instead provide voluntary vocational training to vulnerable people."Most detainees in these four centres were not allowed to leave their room, except to go to the toilet only twice a day," the report said. "In most cases, food was no more than one cup of corn a day and several former detainees complained about the lack of drinking water or the opportunity to wash."