Italian emergency workers have recovered 217 bodies from the wreck of a boat that sank in the Mediterranean in April 2015, killing some 500 refugees, the Navy said on Thursday.

The wreck of a fishing boat that sank in April 2015, drowning hundreds of migrants packed on board, is seen after being raised in the Sicilian harbour of Augusta, Italy, July 1, 2016. | Photo: Reuters

The sinking was one of the worst known disasters involving refugees trying to reach Europe by sea. Thousands of people a year, many of them fleeing war in the Middle East, have crossed the Mediterranean in unseaworthy or overcrowded boats.

In 2015, at least 3,770 people are thought to have died on Mediterranean routes, mostly by drowning when their boats capsized.

The vessel was hauled off the seabed and taken to a naval site in southeastern Sicily last week. Its sinking about 85 miles north of Libya, from where it departed, jolted the European Union into stepping up Mediterranean rescue efforts.

Originally at least 700 people were thought to have died in the disaster, based on survivor testimony. A Navy official said last week he thought some 300 bodies were still in the hold, which added to 169 recovered from the nearby seabed would bring the death toll closer to 500.

A team of 150 professionals and volunteers from the Navy, fire service, Italian Red Cross and a forensic team of Milan university professors have been working around the clock to remove bodies from the fishing boat and examine them.

Autopsies have been carried out on 52 of the victims, and police scientists coordinated by a local public prosecutor have begun making reports on their findings.