At least 219 migrants and refugees are believed to have drowned in the Mediterranean already this year, more than double than during the same period a year ago, the International Organization for Migration (IOM) said on Tuesday.
Following interviews with four survivors of a weekend shipwreck, the agency said nearly 180 people were feared to have been aboard a boat that capsized off the coast of Libya, not 110 as earlier thought.
"So it's almost twice the number of casualties which brings the year total already two weeks into the year to 219 deaths on the Mediterranean," IOM spokesman Joel Millman told a news briefing in Geneva.
The Italian coastguard said the boat had not been found so there was no way to determine the number of passengers. Survivors were taken to Sicily on Monday.
The overall death toll for migrants on the Mediterranean in the first two weeks of 2016 was 91, the IOM said.
IOM officials are also looking into reports of some 25 migrants perishing at sea between Morocco and Spain in recent days, Millman said.
From Jan. 1 to Jan. 15, 2,876 migrants and refugees entered Europe by sea, arriving mostly in Greece and Italy, against 23,664 through the first 14 days of Jan 2016, according to the IOM's latest figures. An agreement between Turkey and the European Union has limited departures from Turkish shores.
In 2016, more than 170,000 irregular migrants entered Greece, with some 80,000 Syrians forming the largest group, Millman said.
Some 41,000 Afghans were the second largest group in Greece, followed by nationals from Iraq, Pakistan and Iran, he said.
Reporting and writing by Stephanie Nebehay