The International Organization for Migration says the shooting was linked to notorious overcrowding at the centre where conditions are deplorable.
Libyan guards shot dead six African migrants in a detention centre in Tripoli on Friday, the International Organization for Migration (IOM) said, denouncing "terrible" living conditions in the overcrowded place.
The shooting took place in the Al-Mabani detention centre where some 3,000 migrants are being held, IOM official Federico Soda told AFP. "Six migrants in total were killed by the guards," he said.
"We do not know what caused the incident but it is in connection with the overcrowding of migrants who live in terrible and tense conditions," he added. "Many migrants escaped during the chaos."
According to Soda, the Al-Mabani detention centre has a capacity of 1,000 detainees but more than 3,000 are crowded there, about 2,000 of them outside the main building but within the complex perimeter.
"Their detention is arbitrary. Many of them have their papers in order but are stranded in the country," he said.
Libya is an important crossing point for tens of thousands of migrants, mostly from Saharan African countries, seeking each year to reach Europe via the Italian coastline, some 300 kilometres away.
Several NGOs and UN agencies regularly denounce the deplorable conditions in detention centres in Libya, where over the past ten years smugglers and traffickers have taken advantage of the climate of instability that followed the 2011 revolt, turning Libya into a hub of human smuggling in Africa.
'Crimes against humanity'
In early October, an "anti-drug" operation carried out by the Libyan authorities in a suburb of Tripoli, which mainly targeted irregular migrants, left one dead and at least fifteen injured, according to the United Nations Support Mission in Libya (UNSMIL). At least 5,000 people, including women and children, have been arrested, according to Médecins Sans Frontières (MSF).
On Monday, a UN expert fact-finding mission released a report denouncing "war crimes" and "crimes against humanity" committed in Libya since 2016, in particular against migrants.
Migrants are subjected to all kinds of violence "in detention centers and by traffickers", according to the text. "Our survey shows that attacks against migrants are committed on a large scale by state and non-state actors, with a high degree of organization and with the encouragement of the state - all aspects that suggest that these are crimes against humanity."
Many journeys linked to illegal immigration have ended in tragedy. The latest occurred on Tuesday when the lifeless bodies of 17 migrants were discovered on the Libyan west coast after their boat sank.
The number of migrants who died at sea trying to reach Europe has more than doubled this year compared to the same period in 2020, according to IOM figures released in July. In September, the IOM counted 1,369 migrants who had drowned in the Mediterranean since the start of the year.
Libya is trying to turn the page on a decade of chaos since the fall of Muammar Gaddafi, killed in a popular revolt.
Overcoming the years of conflict, a transitional government was installed in March, under the auspices of the UN, to lead the country towards elections scheduled for December and January but which remain up in the air due to persisting divisions.