Several hundred migrants are believed to have died after four boats capsized in the Mediterranean.
Italian President Sergio Mattarella said there had been a "migrant tragedy", as unconfirmed reports suggested the vast majority of those on board the vessels were Somalis, trying to cross the sea from Egypt to Europe.
Speaking at a prize giving ceremony in Rome, Mr Mattarella said Europe needed to reflect in the face of "yet another tragedy in the Mediterranean in which, it seems, several hundred people have died".
He did not give any further details.
Around 800 migrants and refugees drowned on April 18th last year, when the overcrowded fishing boat they were attempting to cross the sea in from Libya overturned.
Italian foreign minister Paolo Gentiloni added: "We are looking for more details, information. But what is sure is that we are again with a tragedy in the Mediterranean - exactly one year after the tragedy we had, not in the Egyptian but in the Libyan waters".
"This is another strong reason for Europe to commit itself not in building walls but in strengthening our common commitment towards migration, especially towards Africa".
The Italian coastguard said they knew nothing about the reported disaster.
However, they were involved in the rescue of 108 migrants from a semi-submerged rubber dinghy. Six people died in the incident.
A further 33 - including 10 children - were brought to safety overnight off the eastern coast of Sicily.
It comes as a report by academics accused EU policymakers of "killing by neglect" by reducing search and rescue missions in the Mediterranean.
Mare Nostrum, the Italy-led rescue mission, was scrapped in October 2014 and replaced by Triton, which deployed fewer ships and prioritised deterring migrants over rescue operations.
The change has since potentially cost the lives of more than 1,500 migrants, according to the report 'Death By Rescue: The Lethal Effects Of The EU's Policies Of Non-assistance At Sea'.
A charity warned the numbers of migrants braving the perilous journey by sea to Europe is unlikely to fall - despite an EU deal to deport those who have failed to gain asylum.
"The numbers will not stop coming because they have no choice but to try and reach Europe," said Sarah Tyler, head of communications for Save The Children International.
"What they are leaving behind is not a life that is worth living, many children have told me. So, yes, the safe passage has to be implemented and search and rescue measures need to be continued".
The Irish Defence Forces is set to send another naval vessel to the Mediterranean to help with the humanitarian crisis.
