Pope Francis has described indifference towards the migrant crisis as a “sin” and called detention centres in Libya as “places of torture and despicable slavery”.
The Pope, who has made defending refugees a key part of his time at the head of the Catholic Church, was speaking as he welcomed 33 migrants to the Vatican from a camp on the Greek island of Lesbos.
He said all detention centres, which are overcrowded and a hot spot for human rights violations, should be closed and migrant traffickers punished.
Exact migrant figures in Libya are difficult to determine with many held in unofficial camps where abuse is particularly rife, but the figure is believed to be well over 600,000.
So far in 2019 just under 100,000 migrants arrived by sea to Italy, Greece, Spain, Cyprus and Malta, according the UN’s refugee agency. Some 1,277 are dead or missing.
While the figures are a far cry from 2015 when over a million made the voyage by sea, the percentage of deaths to arrivals has risen sharply.
"How can we fail to hear the desperate cry of so many brothers and sisters who prefer to face a stormy sea rather than die slowly in Libyan detention camps, places of torture and ignoble slavery?", the Pope said.
"How can we remain indifferent to the abuses and violence of which they are innocent victims, leaving them at the mercy of unscrupulous traffickers? Our ignorance is a sin."
Pope Francis criticised the policy of preventing migrants from landing in Europe, which has repeatedly seen rescue ships stranded in the Mediterranean and unable to dock.
This approach has emboldened the Libyan coastguard to lead rescues, which typically sees the migrants returned to detention centres.
"Serious efforts must be made to empty the detention camps in Libya, evaluating and implementing all possible solutions," Pope Francis said.
"We must denounce and prosecute traffickers who exploit and abuse migrants,"
The Pope’s comments came as he unveiled a cross adorned with a life jacket, which had been worn by a migrant who died last year while crossing the Mediterranean.
“I decided to expose here this life jacket, ‘crucified’ on this cross, to remind us that we must keep our eyes open, keep our hearts open, to remind everyone of the absolute commitment to save every human life, a moral duty that unites believers and non-believers,” he said.
In 2016 Pope Francis flew three Syrian families languishing in Lesbos to the Vatican and he has been highly critical of the mistreatment of migrants.