As many as 700 migrants are feared to have died as the vessel they were travelling in sank off the Libyan coast on Sunday.

Italy’s interior ministry reported that only 28 survivors have been rescued, in one of the worst maritime disasters of its kind in the Mediterranean.  The vessel, which was reportedly carrying up to 900 migrants attempting to reach Europe, sank after the refugees on board attempted to catch the attention of a Portuguese merchant ship to rescue them. 

“They wanted to be rescued,” said Barbara Molinario, a spokeswoman for UNHCR. “They saw another ship. They were trying to make themselves known to it,” she added.

The disaster means that some 1,500 migrants have died so far in the Mediterranean in 2015 alone – a figure 30 times higher than in 2014. As many as 400 people drowned to death in a similar incident last week.

Italian Prime Minister Matteo Renzi called people smuggling "a plague in our continent" and called for concerted European Union action to tackle the problem, whilst Malta’s Prime Minister Joseph Muscat accused “gangs of criminals” of being behind the rise in refugees attempting to reach Europe.

"Gangs of criminals are putting people on a boat, sometimes even at gunpoint… They're putting them on the road to death, really, and nothing else," said Mr Muscat.

He told CNN that it was "genocide - nothing less than genocide, really".

Pope Francis also called for greater co-ordination in rescue efforts, stating that those who drowned “are men and women like us – our brothers seeking a better life, starving, persecuted, wounded, exploited, victims of war.”

Save the Children’s chief executive Justin Forsyth, said, “The scale of what is happening in the Mediterranean isn’t an accident, it’s a direct result of our policy. How many more innocent children and their families must die before our leaders act? It is time to put humanity before politics and immediately restart the rescue.”

“Europe cannot look the other way while thousands die off our shores,” he added.