Athens, June 16 (RHC)-- Protests have taken place across Greece over the sinking of a boat carrying migrants and refugees that left at least 78 people dead.  More than 100 people were rescued from a capsized boat off the coast of Pylos but hopes have faded for hundreds of others who were still missing.

A huge search and rescue operation recovered 78 bodies, but authorities estimate the trawler may have carried as many as 750 passengers, who each paid thousands of dollars for passage on the battered vessel.

Al Jazeera’s John Psaropoulos, reporting from the town of Kalamata where the survivors were being held by the authorities, said nine men had been arrested on suspicion of belonging to the smuggling ring that arranged the voyage.  “It’s thought they were junior functionaries, not the ultimate beneficiaries of the $3m this passage may have been worth,” Psaropoulos said.

Greek rescuers on Thursday scoured the Ionian Sea for survivors as hope of finding more people faded.  The vessel sank in international waters, 47 nautical miles (87km) southwest of Pylos, off the Peloponnese coast.  The spot is close to one of the deepest areas of the Mediterranean.

United Nations migration agency, the International Organization for Migration, estimated the number of passengers based on interviews with survivors and said the complement included at least 40 children.

Coastguard spokesman Nikolaos Alexiou told the ERT TV station that “the fishing boat was 25-30 metres long."   “Its deck was full of people, and we assume the interior was just as full,” he said.

Acting migration minister Daniel Esdras said the survivors would eventually be taken to Malakasa migrant camp near Athens by Friday.  Greece would examine their asylum claims, but those not entitled to protection would be sent home, he added.

Thousands of people demonstrated on Thursday in cities across Greece to protest against the authorities’ handling of the shipwreck, as well as the European Union’s migration policies.  Greek authorities were criticised for not acting to rescue the migrants and refugees.

A coastguard vessel escorted the trawler for hours and was present as it sank in minutes.  Greek officials argued that the passengers repeatedly refused assistance and insisted on continuing to Italy.  The vessel appeared to be sailing normally until shortly before it sank and refused repeated rescue offers, they said.

But Alarm Phone, a self-organised hotline for refugees and migrants in distress in the Mediterranean Sea, said they received repeated distress calls from the vessel during the same timeframe.

On Thursday, leader of main opposition party Syriza, Alexis Tsipras, spoke with European Commissioner for Home Affairs Ylva Johansson about the shipwreck tragedy, the party said in a statement.  “This incident demonstrates in the clearest way the failure of the EU to promote a structured refugee migration policy that puts human life as the first priority,” Tsipras said, after visiting the survivors in Kalamata.

Greek Supreme Court Prosecutor Isidoros Dogiakos appointed a Supreme Criminal Court deputy prosecutor to supervise an investigation of the incident.