The "most catastrophic maritime tragedy since WWII". Up to 700 feared dead as asylum seeker ship capsizes.

As many as 700 are feared dead after a asylum seeker ship capsized in the Mediterranean Sea prompting a major search operation.

A boat carrying as many as 700 people has capsized off the coast of Libya in the Mediterranean Sea, prompting a major search operation.

Some outlets are reporting there could have been as many as 900 men, women and children on board.

The vessel, thought to be just 20m long, capsized at midnight local time in Libyan waters south of the Italian island of Lampedusa.

So far only 28 people have been rescued and 24 bodies retrieved.

Harrowing images have been relayed on European news sources of asylum seekers clinging to the top of the capsized boat, while others struggle in the water.

The boat initially set off from Egypt and then stopped off on the Libyan coast near the city Zuwarah to pick up more passengers

Malta’s prime minister, Joseph Muscat, said “They are literally trying to find people alive among the dead floating in the water.

“This could possibly be the biggest tragedy to have ever taken place in the Mediterranean. Children, men, and women have died.”

The Italian Prime Minister Matteo Renzi has been criticised by aid agencies for not doing enough to prevent migrants drowning in the Mediterranean.

He confirmed in a press conference overnight that Italy had called an “extraordinary European council” meeting as soon as possible to discuss the recent tragedy.

He said “There is a scourge in the Mediterranean and on our continent, this is the a new 21st-century slavery trade.

“We must block these new slave traders because it is about human dignity and security.”

General Antonino Iraso of the Italian Guardia Finanza police, which is involved in the rescue attempt, said that if the numbers were confirmed it would be the worst shipping disaster since the Second World War.

“I express my deepest pain in the face of the tragedy. I appeal to the international community to act quickly and decisively to avoid repeating similar tragedies. They are men and women like us, our brothers who search for a better life, persecuted, injured, exploited, victims of war, searching for a better life, searching for happiness.”

The United Nations Refugee Agency (UNHCR) said that should these figures be confirmed, then so far in 2015 1,600 people have died attempting to reach Europe by boat.