Migrants, who are part of a group intercepted aboard a makeshift boat off the coast in the Mediterranean sea, stand on a rescue boat as they arrive at a port in Malaga, southern Spain, May 19, 2016. REUTERS/Jon Nazca

Over 700 migrants and refugees are feared dead in three shipwrecks in the Mediterranean south of Italy this week, the United Nations' refugee agency told the Associated Press (AP) Sunday. The ships capsized as hundreds tried desperately to reach Europe in rickety smuggling boats.

Carlotta Sami, spokeswoman for United Nations High Commissioner for Refugees (UNHCR), told AP by phone Sunday that an estimated 100 people are missing from a smugglers' boat that capsized Wednesday. Several pictured were reportedly taken by the Italian navy as it rushed to rescue those who were on board the boat. The news comes as Europe continues to cope with the influx of migrants and refugees, several of whom drown each year attempting to cross the perilous Mediterranean Sea crossing.

Nearly 550 others are also unaccounted for after a smuggling boat capsized Thursday morning after leaving the western Libyan port of Sabratha a day earlier, Sami said. The boat, which was carrying about 670 people, didn't have an engine and was being towed by another packed smuggling boat before it capsized, Sami said, citing refugees. Nearly 100 people were rescued by international patrol boats and 15 bodies have been so far recovered, AP reported, citing UNHCR.

A third shipwreck Friday left an unknown number of people missing, Sami said, adding that 135 people were rescued and 45 bodies have so far been recovered.