GENEVA, May 24 (Xinhua) -- The International Organization for Migration (IOM) reported Friday that 19,830 migrants and refugees have entered Europe by sea through May 22 this year, roughly a 30-percent decrease from the 28,325 arriving during the same period last year.

Arrivals to both Spain and Greece account for 86 percent of all this year's arrivals, IOM said at a news briefing here Friday.

Deaths recorded on the Mediterranean Sea routes this year so far are at 512 individuals, or four-fifths of the 638 deaths confirmed during the same period in 2018, IOM added.

Being the sixth year of IOM's efforts to systematically record deaths on migration routes worldwide through its Missing Migrants Project, IOM said Friday that since the beginning of 2014, the project has recorded the deaths of 31,947 individuals, including 999 in 2019.

IOM said that due to the challenges of collecting information about these people and the contexts of their deaths, the true number of lives lost during migration is "likely much higher".

According to IOM's Friday news briefing here in Geneva, this past week was marked by several tragedies in different regions of the world.

In the Indian Ocean, it said, three people lost their lives on the often-overlooked migration route from the islands of Comoros to the French archipelago of Mayotte.

"These are the first deaths recorded on this sea crossing in 2019. This route claimed the lives of at least 18 people in 2018 and 31 in 2017," IOM said.

On the U.S.-Mexico border, a 32-year-old Mexican man drowned in the Rio Grande/Rio Bravo on May 17, near Ciudad Acuna, Coahuila, Mexico. This latest tragedy brings to 38 the number of lives lost recorded by IOM team in the Rio Bravo since the beginning of this year.

On the Canada-U.S. border, IOM cited reports of the death of a 32-year-old Dominican man when he was trying to cross the border near Lake Champlain, Quebec last month.

Including this latest death, to date at least 271 people have lost their lives in the Americas in 2019, compared with 189 recorded through this point in 2018, IOM said.