Conditions, say the UN, are inhuman and degrading. There’s little water, food is scarce and disease is rampant.
This is the Zintan detention centre in Libya, where things have got so desperate the migrants from across Africa who are being held there are organising protests.
Now, Channel 4 News has obtained shocking pictures from inside the camp, showing just how perilous the situation there has become.
Warning: there are distressing images in this report.