At least 365 migrants drowned in the past three days in the Mediterranean in six incidents, making this November already six more times more deadly than the same month a year ago, the International Organisation for Migration says.
"This is really a calamity in plain sight," IOM spokesman Leonard Doyle told a news briefing in Geneva on Friday.
"We are seeing really tragic scenes of rubber rafts going under the seas in the Mediterranean in the middle of winter."
The latest drownings, mostly West Africans leaving Libya for Italy, bring migrant deaths in the Mediterranean so far this year to 4636, he said.
There have been 1000 more deaths this year among roughly half as many people trying to reach Europe by sea, with some 343,589 arrivals so far this year, against 728,926 last year at this point, according to IOM figures.