POZZALLO, Italy (AP) — The UN refugee agency says over 700 migrants are feared dead in three Mediterranean Sea shipwrecks south of Italy in the last few days as they tried desperately to reach Europe in unseaworthy smuggling boats.

Carlotta Sami, spokeswoman for UNHCR, told The Associated Press by phone Sunday that an estimated 100 people are missing from a smugglers' boat which capsized Wednesday. The Italian navy took horrific pictures of that capsizing even as it rushed to rescue all those thrown into the sea from the boat.

She said about 550 others are missing from a smuggling boat that capsized Thursday morning after leaving the western Libyan port of Sabratha a day earlier. She says refugees say that boat, which was carrying about 670 people, didn't have an engine and was being towed by another packed smuggling boat before it capsized. About 25 people from the capsized boat managed to reach the first boat and survive, 79 others from it were rescued by international patrol boats and 15 bodies were recovered.

In a third shipwreck on Friday, Sami says 135 people were rescued, 45 bodies were recovered and an unknown number of people — many more, the migrants say — are missing.

Survivors are being taken to the Italian ports of Taranto and Pozzallo. Sami says the U.N. agency is trying to gather information with sensitivity considering that most of the new arrivals are either shipwreck survivors themselves or traumatized by what they saw.

Italy's southern islands are the main destinations for countless numbers of smuggling boats launched from the shores of lawless Libya each week packed with people seeking jobs and safety in Europe. Hundreds of migrants drown each year attempting the dangerous Mediterranean Sea crossing.