Two migrants have died after their boat sank while trying to cross the Mediterranean Sea to European shores, Spain's maritime rescue service said Sunday.

The service said that both were men of sub-Saharan origin and that their boat was located late Saturday about 10 miles (16 kilometers) west of the Island of Alboran.

The first man was found dead in the water by a fishing boat that had taken on 32 migrants from the sinking vessel and saved another two who were overboard.

A rescue helicopter and ship arrived in time to pull two more men from the water. The rescue service said one of the men could not be saved.

The service said that it also saved another 51 migrants from two other boats between late Saturday and Sunday morning. It added that Moroccan officials reported they saved 18 more from two small boats.

Europe's border watchdog said Friday that 22,880 migrants had arrived in Spain last year by sea, up from 10,231 in 2016. It warned it expects the number of migrants using the western Mediterranean route to Europe to increase this year.

The International Organization for Migration says 2,583 migrants entered Europe by sea this year through Wednesday, and that 199 others died en route.

Many migrants are packed into tiny boats unfit for the perilous crossing.