European Union Official Calls for More Surveillance of Migrant Routes BRUSSELS - A senior European Union official called on Tuesday for vastly expanded patrols of Mediterranean waters, as horror mounted over the deaths of hundreds of African migrants near Sicily last week. The bloc needs "a wide operation that will cover the whole Mediterranean from Spain to Cyprus in order to be able to prevent future catastrophes and save more lives," Cecilia Malmstrom, the union's commissioner for home affairs, said at a news conference after a meeting of justice and interior ministers in Luxembourg. "I've asked member states to give their political support and also make available the necessary resources," said Ms. Malmstrom, who must rely on member governments to finance and carry out search-and-rescue efforts. The statement from Ms. Malmstrom was one of the strongest calls for a response to the disaster on Thursday, when an overstuffed and rickety trawler carrying an estimated 500 migrants fleeing war and poverty caught fire and capsized near the Italian island of Lampedusa. Ms. Malmstrom said she would join Enrico Letta, Italy's prime minister, and José Manuel Barroso, the president of the European Commission, on Lampedusa on Wednesday to speak with residents and victims of the shipwreck. Divers on Tuesday retrieved another 19 bodies from the wreckage, raising the death toll to 275. The ship is submerged under 165 feet of water about a quarter-mile from Lampedusa. Officials from the Italian Coast Guard said the death toll was expected to grow as the search continued. Even as the European Union commissioner sought to prevent more tragedies at sea, the debate over how to treat people caught making landfall became more fraught, as the Italian authorities placed the 155 survivors of the capsizing under investigation for illegal immigration. Under a 2009 law, illegal migrants who are not asylum seekers can face penalties for entering Italy, a situation some experts described as absurd. "If prosecutors have the pilot and the boat, migrants are logically the victims of the smuggling," Alberto Di Martino, a professor of criminal law and immigration at the University of Pisa, said by telephone. They are not liable for any crime. On Tuesday, prosecutors in Agrigento, Sicily, said they were holding a 35-year-old Tunisian man on suspicion of being one of two men in charge of piloting the boat. Prosecutors said the man, who has not been formally charged, could face a prison sentence of more than 20 years if found guilty of multiple counts of committing manslaughter, abetting illegal immigration and causing a shipwreck. Ms. Malmstrom said the additional patrol work in the Mediterranean should be undertaken by Frontex, the European Union border security agency, which relies on financing from the bloc's governments to pay for surveillance equipment like planes and boats. Ewa Moncure, a spokeswoman for Frontex, which is based in Warsaw, said Tuesday that the agency had already deployed four coastal vessels and two aircraft this year as part of an operation to patrol the central Mediterranean route used by the migrants who died near Lampedusa. Ms. Moncure said Frontex was waiting for the outcome of the meeting of justice and interior ministers in Luxembourg before issuing a statement about any additional patrol work in the Mediterranean. "But with such high numbers of migrants arriving," she said, "we are definitely going to prolong our operation beyond October." Analysts warned, however, that allocating more resources to Frontex, which works primarily to coordinate member states" border operations, would not automatically make the agency more effective. "Frontex would be very enthusiastic for this kind of wider role, but there is a big question over how this would really work, given that Frontex does not have any direct operational powers," said Joanna Parkin, a migration specialist at the Center for European Policy Studies, in Brussels. "A second serious question," she said, "is whether Frontex should have this kind of enhanced role given the ongoing questions about whether Frontex can be held responsible for failures to protect migrants on the Mediterranean Sea or whether it can ensure that potential refugees are given proper protection when they reach Europe, rather than get pushed back." Many of the migrants on the central Mediterranean route originate from countries in the Horn of Africa and western Africa, and they use Libya as a nexus before starting their journey toward Europe, according to a statement that Frontex posted on its Web site. Most of those migrants land on Lampedusa or Sicily, but others make landfall elsewhere in Italy, usually around Calabria and Puglia, the agency said. During the first nine months of the year, more than 31,000 migrants arrived in the European Union using the central Mediterranean route, most of them Eritreans, Somalis and other sub-Saharan Africans, as well as Syrians, Frontex said. Migratory pressure this summer was comparable to that in the summer of 2011, when civil unrest in Tunisia and Libya led over the course of that year to about 60,000 arrivals on the central Mediterranean route, the agency said. Many migrants make the journey aboard overcrowded wooden fishing boats that are prone to sinking or capsizing in high seas and are ill equipped, with poor engines and navigation systems. "Often, the drivers of these boats leave them adrift relatively near the Italian shores and go back where they came from," Renato Di Natale, the chief prosecutor in Agrigento, said by telephone.