TRIPOLI, Libya, April 14 (UPI) -- About 400 migrants have likely drowned in the Mediterranean Sea after their boat capsized near the Libyan coast, a rights group said Tuesday.
Some of the 144 survivors rescued by the Italian navy and coast guard on Monday told Save the Children, an international non-governmental organization that promotes children's rights, that a group of approximately 550 migrants were on the boat when it capsized one day out from the Libyan coast.
Save the Children said several of the survivors were young men who were "probably minors."
So far only nine bodies have been recovered, but since Friday more than 7,000 migrants have been rescued from the Mediterranean Sea, according to the European Union.
On April 5, the Italian navy and coast guard rescued up to 1,500 migrants in the same waters over a period of 24 hours.
Each year thousands of people fleeing violence in Africa and the Middle East drown in the Mediterranean while traveling over rough seas on shoddy boats.
According to the Office of the United Nations High Commissioner for Refugees, 218,000 people crossed the Mediterranean using irregular routes in 2014, of which 3,500 died. Italy alone dealt with about 170,000 such refugees in that time.
"Mare Nostrum" was the name given to Italy's migrant rescue operations, but right-wing politicians expressed concerns about its daily cost and the possibility that Middle Eastern and North African terrorists might make their way into Italy's borders.
Mare Nostrum ended late last year and a smaller EU operation known as "Operation Triton" took over, but U.N. leaders predicted a higher degree of migrant deaths due to lighter efforts.
In March a EU official warned that up to a million migrants could leave Libya for Europe in 2015.
Officials say during the first two months of 2015 there has been a 43 percent increase in migrant arrivals in Europe over January and February 2014.