At least 79 people have died off the coast of southern Greece after a fishing boat allegedly carrying hundreds of migrants capsized and sank, authorities said Wednesday.
A large search and rescue operation was launched in the area around the shipwreck which is the deadliest off Greece this year.
"So far 104 survivors were brought to shore while 32 bodies [now 79] were recovered. Search and rescue efforts continue and we fear more lives were lost.
"Initial reports suggest up to 400 people were onboard," the United Nations's Migration agency said.
Authorities said 104 people have been rescued so far after the boat sank overnight in international waters some 75 kilometers (45 miles) southwest of Greece's southern Peloponnese peninsula.
The spot is close to the deepest area of the Mediterranean Sea - and such depths could hamper any effort to locate a sunken metal vessel.
Twenty-five survivors were hospitalised with symptoms of hypothermia after they were rescued some 46 miles southwest of Greece’s southern Peloponnese region.
At the southern port of Kalamata, dozens of rescued migrants were taken to sheltered areas set up to receive dry clothes and medical attention.
Katerina Tsata, head of a Red Cross volunteer group in Kalamata, said the migrants were also given psychological support.
"They suffered a very heavy blow, both physical and mental," she said.
The Greek coast guard said 79 bodies have been recovered so far. It said the survivors included 30 people from Egypt, 10 from Pakistan, 35 from Syria and 2 Palestinians.
"Yesterday, we were alerted by a boat in distress in the Greek SAR zone. It had left Libya. According to the people, there were 750 people on board. We now hear reports of a shipwreck and fear they are true", the Twitter account 'Alarm Phone' wrote.
The account is an official independent support line for people crossing the Mediterranean Sea.
The Associated Press says the boat was heading for Italy from the Tobruk area in eastern Libya.
A mammoth search operation is underway with six coast guard vessels, a navy frigate, a military transport plane, an air force helicopter, several private vessels and a drone from the European Union border protection agency, Frontex all helping to recover people.
Libya remains Africa’s main departure point to Europe for migrants seeking safety and opportunity and the country is continually facing economic collapse, political instability, and ongoing conflict between violent militias.
Many migrants in Libya also come from Niger and Chad, two African nations on Libya’s southern border.
At the end of May, the European Union called on Greece to investigate allegations that it is abandoning migrants at sea as fears grow that the centre-right government in Athens is violating EU law.
Greece criminalises rescue operations for migrants with severe punishment.
The country's New Democracy leader Kyriakos Mitsotakis has postponed his campaign rally in the western port city of Patra following the news of the shipwreck.
