The United Nations urged the European Union to take action to prevent the death of more migrants in the Mediterranean Sea, after the recent boat tragedy with 78 bodies being found, potentially claiming hundreds of lives of the 500 to 700 onboard.

"It is clear that the current approach to the Mediterranean is unworkable," said Federico Soda, the director of the Department of Emergencies at the U.N.'s International Organization for Migration.

"States need to come together and address the gaps in proactive search and rescue, quick disembarkation, and safe regular pathways."

Gillian Triggs, an assistant high commissioner at the United Nations High Commissioner for Refugees (UNHCR), said: "The EU must put safety and solidarity at the heart of its action in the Mediterranean."

Triggs called for greater coordination, solidarity and responsibility-sharing among EU states.

A fishing boat, which is thought to have been carrying between 500 and 700 passengers, went down in international waters off Greece in the early hours of Wednesday. A little over 100 people have been found alive and search efforts were expected to be formally called off on Friday.

Greek coast guard ‘directly involved’ in deadly shipwreck: EU lawmaker

Survivors have said the Hellenic Coast Guard was "directly involved and might have caused" the deadly shipwreck off the southern coast of Greece, according to an EU lawmaker.

"Greek authorities knew that a ship carrying asylum seekers is in danger in their waters, but didn't start the rescue for hours," Erik Marquardt, a German Member of the European Parliament from the Green Group, told Anadolu Agency (AA).

"Some survivors even indicate that the Greek coast guard was directly involved and might have caused the shipwreck," he added.

At least 78 people died and hundreds more remain missing after a fishing boat carrying refugees and migrants sank off the southern coast of Greece, one of the deadliest such disasters this year.

A total of 104 people were rescued, but the fatality count is expected to rise as survivors said the vessel was carrying more than 600 migrants, mostly from Pakistan, Egypt and Syria.

Europe is building a "wall of lies" about what happens at its borders, said Marquardt, who is a key EU lawmaker on migration policy as vice-chair of the European Parliament's Committee on Development and a member of the Committee on Civil Liberties, Justice and Home Affairs.

He said an independent investigation could ascertain the exact details of the tragedy.

He said the latest incident in Greek waters "is quite usual," as people are dying every day at the EU's external borders while "authorities don't comply with the international law of the sea."

"Governments of the European Union are building a wall of lies of what is happening at their external borders," Marquardt asserted.

"We know that pushbacks are happening every day, and systematically."

He said these lies are "an attack on democracy" for which "Europeans should be ashamed."

"Thousands of people die on a yearly basis just because we cannot find an answer (to the migration policy)," he said.

"Smugglers are bad people who use the suffering of others, but in the end, we are not really better if we don't react when people are in danger."

‘Building a fortress'

The EU "cannot build a wall of dead bodies at our external borders just because we have some interests when it comes to migration policy," said Marquardt.

He said the tragedy has once again directed the "spotlight on what is happening at the EU's external borders."

However, having been present "at too many minutes of remembering" victims of similar catastrophes, he said it was unlikely that it would be a turning point in the approach of EU governments.

Regarding last week's EU agreement on migration policy reform, Marquardt said it was a "very bad decision that writes populism into law," and reflects "the political interest that nobody should arrive to Europe."

"It sends a signal to the world that Europeans think they are better than others," he said, adding that despite their tall words, Europeans treat people "contrary to human rights."

"It sends a signal that Europeans are not able to deal with migrants as human beings, (and are) only building a fortress," he said.