The migrants, mostly from West Africa, were cast adrift in rough and icy conditions
The drowning of more than 300 migrants in the Mediterranean Sea this week could have been prevented with better EU lifesaving provisions, experts say.
The UN's refugee agency, UNHCR, says more migrants are dying because search and rescue efforts have been reduced.
Italy's major patrol and rescue operation ended last year. A smaller scale EU operation, Triton, took over.
The UNHCR says about 3,500 migrants died trying to cross the Mediterranean Sea to Europe in 2014.
In the latest disaster, more than 300 people drowned after the four dinghies they were travelling in got into trouble after leaving Libya for Europe.
"We warned everybody in October that by lowering the tension and the operational capacity of the search and rescue operation, this might happen," Carlotta Sami, the UNHCR's representative for southern Europe, told the BBC.
The coffins containing bodies of immigrants who died where taken to Porto Empedocle in Sicily
She warned that tragedies such as this would happen again if the EU did not take urgent action to scale up its search and rescue operation.
"The EU has done too little too late," she said. "It's too late because the trend of influx of refugees and migrants crossing the Mediterranean will not stop."
'Political decision'
In November, Italy ended its operation known as Mare Nostrum, which was launched in October 2013 in response to a tragedy off Lampedusa island, in which 366 people died.
The EU now runs a border control operation, called Triton, which only operates close to Europe's coast and has fewer ships.
The International Organization for Migration (IOM) says more people could have been saved in the latest disaster.
"We think it could certainly have been prevented had there been a better life-saving flotilla or task force in place," said Leonard Doyle, IOM spokesman.
The Italian coast guard rescued scores of people from the stricken dinghies this week
The decision to end Mare Nostrum sparked warnings that it would lead to more deaths.
But other European countries, including the UK, said a rescue service could encourage more migrants.
"The Mediterranean rescue flotilla, which was known as Mare Nostrum, isn't there anymore because a political decision has been taken that this was attracting people to attempt to cross the Mediterranean," said Mr Doyle.
"If anybody believes that taking away the lifeguards... taking away the security and the rescue mission... [is] going to deter people, that's just frankly incorrect."
Even deadlier
Meanwhile the European Border Agency Frontex, which carries out operation Triton, says it is doing all it can to save as many people as possible
"Our mandate as an agency is border control," said Frontex spokesperson Ewa Moncure.
She said Operation Triton suspended its border control activities when necessary to conduct search and rescue operations. But she stressed that Triton was not designed to replace the work of Mare Nostrum.
Operation Triton has only a third of the budget of the Italian operation
The UNHCR says almost 3,500 people died attempting to cross the Mediterranean Sea to reach Europe in 2014, making it the world's most dangerous sea crossing for migrants.
More than 200,000 people were rescued in the Mediterranean during the same period, many under the Mare Nostrum mission prior to its abolition.
The IOM warned that 2015 could be even deadlier, pointing out that the latest incident comes on top of 115 deaths reported in the Mediterranean since the beginning of the year.
That compares to just 27 deaths during the same period last year, according to the IOM.
Nils Muiznieks, the Council of Europe's Commissioner for Human Rights, said Europe as a whole needed to take responsibility.
"The Mediterranean is a European sea and a European approach is needed," he said.
"The big dilemma is about disembarkation. If you save somebody where do you take them afterwards and process their asylum claim, or if it's not about protection needs who takes responsibility for returning [them]."