Italian, Maltese and US ships were involved in a vast operation to rescue migrants packed in 25 vessels on their way from Libyan shores, part of a sharp increase in arrivals because of improved weather.
Thousands of migrants – mainly from Eritrea and Syria but also sub-Saharan Africa – have arrived or are on their way in what Malta said was the "biggest" search and rescue operation in recent years.
Many of the asylum-seekers intercepted are being taken for processing to ports in Sicily, where local officials complain they are no longer able to cope.
The Italian navy said one boat reaching the port of Pozzallo in southeast Sicily also bore the bodies of three migrants who died during the crossing.
Pozzallo has taken in more than 500 migrants over the past 24 hours. Its mayor, Luigi Ammatuna, told the La Stampa daily that the situation was becoming "untenable", pointing out that tourists are beginning to cancel their summer holidays because of the migrant arrivals.
Italy said that more than 50,000 migrants have landed since on its shores the start of the year – around the same numbers as for the whole of last year.
Malta said 2,200 have arrived on its islands.
Gil Arias Fernandez, the head of Frontex, the European Union border coordination agency, said recently that "hundreds of thousands" of migrants were currently in Libya and hoping to leave as soon as possible because of growing lawlessness.
Italian Interior Minister Angelino Alfano estimated that number at between 400,000 and 600,000 people.
Maltese Prime Minister Joseph Muscat criticised the European Union in an interview with One Radio saying: "Europe has forgotten everyone. When the crunch came, we only found the Americans to help us."
In Sicily, Leoluca Orlando, the mayor of Palermo, said Europe was being "insensitive".
Enzo Bianco, the mayor of Catania, called on Prime Minister Matteo Renzi to declare a state of emergency.
"The credibility of European institutions is teetering. We have to face unbearable statistics," said Lillo Firetto, the mayor of Porto Empedocle.
Michele Cercone, the spokesman for the European Union Home Affairs Commissioner Cecilia Malmstroem, said there would be "full support from the Commission by any means possible".
But he pointed out that Italy and Malta "are the main beneficiaries of EU funds for border surveillance and urgent measures have been taken".
Cercone said Italy had received an extra €30 million ($41 million) since twin shipwreck tragedies in October last year in which more than 400 migrants drowned trying to reach Italian shores.
"We have extended two Frontex missions to support Italy. We are prepared to discuss additional measures of support," Cercone said.
"As for the solidarity of other member states in areas of national competence, we agree that those who are not facing strong migratory and asylum pressure should and can do a lot more," he said.
Following a shipwreck near Libyan shores in May, Renzi launched a scathing attack on Europe saying that it was leaving Italy "alone".
"It is not possible to bail out states and banks and leave mothers and children to die," he said.
Alfano has also threatened that without more assistance he could authorise asylum-seekers who reach Italy to travel to other parts of Europe in defiance of EU rules that say the migrants must stay in the country where they file their asylum request.