Shocking images expose the secret El Salvador prison pens where gang members are held for years in sweltering, cramped and diseased conditions. Inside the prison the guards are too afraid to enter.

The photos are by New York-based British photographer Giles Clarke, whose work published originally in August 2013, uncovers the inhumane conditions of El Salvador’s gang prisons in a series he calls Caged In El Salvador.

Whilst in El Salvadore on assignment in May 2013, Clarke got a first hand look at the 12×15 ft cages – “a sweltering enclosure ringed by a high, barbed wire wall” – full of prisoners. There were three, one for each gang – the two main street gangs are known as ‘Mara Salvatruchas’ (MS-13) and ‘Barrio18’ (M18)- and another for ‘common criminals’.

“In one of the cages I counted thirty five men jammed into a space originally designed to be 72-hour holding cell.” wrote Clarke.

Read here the full report and all the photos.