Warning: Graphic content

On a medical ship off the Italian coast, rescued migrants are colouring in a map of Africa, where many started their perilous journeys toward Europe.  

The countries are brightly coloured in yellow, green, purple and red. Libya however, a common transit country from sub-Saharan Africa into Italy, is black.

For many of the migrants, the country evokes painful memories: abuse, torture and trafficking. 

Libya has been singled out as a dangerous country for migrants, and a UN report last year revealed "crimes against humanity" inflicted on the most vulnerable.

For some aboard the Geo Barents ship run by medical charity Doctors Without Borders (MSF), the dangers are all too familiar. 

"I was tied up, beaten, electrocuted," said 25-year-old Eritrean refugee John, who gave only one name. 

He explained how he fled authoritarian Eritrea in 2018, crossing through Ethiopia and Sudan before arriving in the southeastern Libyan city of Al Kufra four years ago. 

"I was abducted from Al Kufra and sold to traffickers. And then to others," he told AFP. 

He eventually escaped, boarding a dinghy headed for Italy, from which he was rescued in April by the Geo Barents.

He like others has received medical care on board the ship, where migrants also spend time doing activities like the map colouring exercise. 

John colours Libya in black to signify the pain he experienced during his time there. 

"There is no government in this country," he said. "No laws." 

'Lots of beatings'

John is one of the tens of thousands of migrants who attempt the dangerous and often deadly crossing from Libya to Italy every year. More than 31,000 made the journey by sea last year, according to UN figures. 

Many stream to Libya from elsewhere in Africa, boarding precarious vessels to cross the Mediterranean toward Italy. 

AFP could not independently verify details of John's account, but MSF doctors on the Geo Barents say many migrants arrive with chilling reminders of their time in Libya. 

"We see a lot of them with actual physical evidence of violence, injuries that cause long-term problems," MSF doctor Mohammed Fadlalla told AFP. 

"We commonly see bullet wounds, burns, evidence of electrocution, lots of beatings." 

Many migrants land in the hands of traffickers in Libya who demand hefty sums in exchange for their freedom. Attempts to escape can be a death sentence.

The Geo Barents helps those lucky enough to flee, trawling the waters of the central Mediterranean near Italy and Libya in search of migrant boats.

It stops in Italian or international waters - never Libyan waters - and takes in migrants in need, sometimes for as long as two weeks, before they are sent to Italy.  

Fadlalla said medics on the ship often use scars or bruises to piece together what happened to the migrants - a kaleidoscope of trauma used to compile accounts of human rights violations. 

Others need extensive mental and emotional support.

"A lot of these survivors who have suffered this torture have psychological difficulties as well," said Fadlalla. 

"Fear, difficulty sleeping, flashbacks, anxiety, depression."

'Robbed, beaten'

Libya, wracked by conflict since the 2011 overthrow of dictator Moamer Kadhafi, has gained a notorious reputation for migrants on the dangerous route to Europe. 

A UN fact-finding mission last year found some of the abuses faced by migrants there could be classified as "crimes against humanity". 

"Violations against migrants are committed on a large scale by state and non-state actors, with a high level of organisation and with the encouragement of the state," one of the UN experts, Chaloka Beyani, wrote.

Lawyer Jelia Sane, who specialises in refugee law and human rights, condemned European governments for intercepting migrant boats coming from Libya, urging them to offer safe and legal routes. 

"The evidence of the plight of refugees and migrants in Libya can no longer be ignored," said Sane, from London's Doughty Street Chambers.

And for those who have been tortured, access to "full rehabilitation services, as required by international law", should be offered, she said.

Senegalese migrant Eladj Ndiaye still bears the evidence of such abuse. 

The 19-year-old has scars on his scalp and under his lip from when he was beaten with a glass bottle by his captors. They held him for several weeks in Libya, he said.

"Everywhere in Libya you are robbed, you are beaten," he added.

Despite the known risks - and mounting evidence of abuses - migrants continue to trek toward Europe. 

Eritrean refugee John knew what he could face, but went anyway. 

"We know it's dangerous. But we want to join Italy," he said.