Police in Sicily have arrested three Egyptians who allegedly were in charge of a smuggling boat on which a 10-year-old Syrian girl with diabetes died after the smugglers threw her insulin overboard.

Around 40 migrants died in the Mediterranean on Sunday, according to survivors of the journey who arrived on the southern Italian island of Sicily, local Save the Children spokeswoman Giovanna Di Benedetto said.

The Save the Children aid group is reporting another migrant tragedy in the Mediterranean, with survivors saying many of their fellow passengers fell out of a rubber boat and are feared to have drowned as a rescue vessel neared.