Hundreds of migrants are feared dead in the Mediterranean Sea after their boat capsized while en route from Libya to Italy, survivors told aid workers.
The boat had 550 people on board when it left Libya and capsized some 24 hours into its journey, according to the Italian division of Save the Children, although it is not yet clear when the boat encountered trouble.
Italian coast guard officials rescued about 150 people and brought them to shore at Reggio Calabria on Tuesday, but hundreds more were left unaccounted for, Save the Children said in a statement.
The organization said many young boys are likely to be among the victims.
Most of those on the boat are believed to be from sub-Saharan Africa, a Save the Children spokesperson told Reuters.
"Many of them have been through experiences of atrocious violence ... and have lost friends, relatives, or parents, even in recent shipwrecks," said Valerio Blacks, Save the Children Italia's CEO.
Nearly 8,000 people have been rescued in the Mediterranean since the beginning of April, according to the Geneva-based International Organization for Migration. Some 5,600 people were rescued between Friday and Monday alone.
Before the latest incident, more than 500 migrants had been killed while making the perilous crossing, compared to 47 fatalities for the same period last year, the International Organization for Migration reported.
The Italian government expects the number of migrants seeking passage to Europe via its territory to increase as weather improves in the warmer months.