The U.N. migration agency said Friday that a shipwreck off Libya and other recent maritime incidents have raised its estimated death toll among migrants who tried to cross the Mediterranean past the "grim milestone" of 20,000 deaths since 2014.

Paul Dillon, spokesman for the International Organization for Migration, pointed to incidents including the presumed drowning of 91 people who went missing from a dinghy that left Garabulli, Libya, on Feb. 9, and the disappearance of a ship that set off from Algeria on Feb. 14.

IOM noted Friday that the yearly death toll has declined each year since 2016, when over 5,000 people lost their lives while attempting Mediterranean crossings.

The agency reiterated its call for "expanded safe, legal pathways for migrants and refugees" to help reduce the incentive of migrants to choose irregular channels, and "to help prevent the unnecessary and avoidable loss of lives."

IOM also lamented cases of "ghost boats" or "invisible shipwrecks" that are often reported by nongovernmental organizations that receive calls from migrants facing trouble at sea, or from relatives searching for lost loved ones.

"Two-thirds of the fatalities we have recorded are people lost at sea without a trace," said Frank Laczko, director of IOM's Global Migration Data Analysis Center.

"The fact that we have reached this grim new milestone reinforces IOM's position that there is an urgent need for increased, comprehensive (search and rescue) capacity in the Mediterranean," he added.