Athens - More than 4,000 inmates at 21 prisons across Greece continued their hunger strike for a second week on Tuesday, with some sewing their mouths shut to protest overcrowding, drug dealing and lengthy pre-trial detention periods.

Some 4,800 inmates, including Athens' top-security Korydallos prison and the Alikarnassos prison on the Mediterranean island of Crete, initially launched the strike on November 3.

The detainees have been drinking fruit juice and water but have refused solid food.

Reports said 20 inmates at two prisons in central Greece sewed their mouths shut to drive their point home while inmates at a woman's prison have refused to drink water during their hunger strike.

"Yes, there are inmates at the prisons in Trikala and Amfissa, located in central Greece, which have sewed their mouths shut using needles and thread," Ioanna Kourtovik, a lawyer for the inmates told Deutsche Presse-Agentur dpa in a telephone interview.

"The majority of the inmates which have done this are foreigners but there are also cases of Greek nationals which have done this - as you can imagine the conditions in prisons are bad for the Greeks but are even worse for the foreign nationals."

Aside from the inmates on hunger strike, another 4,000 continued to boycott their prison's mess halls for a second week to protest the poor conditions at detention centres across the country.

Protesters, whose cause has been backed by the Coalition of the Radical Left (SYRIZA) and other left-wing parties, object to overcrowding and are demanding better jail conditions, including proper medical care and restrictions on the time that detainees awaiting trial must spend behind bars.

They also object to the drug dealing that goes in many prisons.

A group called Initiative for Prisoners' Rights condemned the state for the drug-related death of an inmate in a jail on the Aegean island of Chios.

"People who are addicted to drugs do not belong in prison but in rehabilitation centres," the group was quoted by the Greek daily Kathimerini as saying.

Last week, Justice Minister Sotiris Hatzigakis announced a number of reforms aimed at improving conditions for inmates and offering additional support for the rehabilitation of drug addicts, who comprise a large proportion of inmates in Greek prisons.

According to the Council of Europe, detainees in Greece have to wait an average of 12 months in pre-trial detention before they go to trial, nearly three times that of other European Union states.

Prisoners are also demanding that social and political leaders be granted easier access to prisons.

Greece's prisons are among the most overcrowded in Europe with 10,983 inmates crammed into jails designed to hold just 7,543. (dpa)