China plans to spend 46.3 billion yuan (US$7.2 billion) upgrading police-run detention houses in the coming five years, an official with the Ministry of Public Security said Saturday.

The money will be used to improve conditions of dentention houses, protect basic human rights of detainees, basically solve the problem overcrowdiness of detention houses and build more rooms for lawyers to meet detainees, Zhao Chunguang, director of the ministry's prison administration bureau, said at a seminar.

Zhao also said that the regulations on detention houses are being revised to better protect the legitimate rights of detainees.

According to the official, over the past two years, the ministry has improved supervision to ensure proper management of detention centers across the country.

To prevent "inmate bullying", alarm devices were installed in every ward, Zhao said.

So far, over 2,000 detention houses have been open for public visit. Those invited to visit the facilities are from all circles of life, including journalists and family members of the detainees, according to the official.