(CNN) -- The death of more than 300 African migrants in a shipwreck off the Italian island of Lampedusa in early October has shone a spotlight on illegal immigration to Europe. But although the tragedy at Lampedusa shocked the world, it has done little to dissuade migrants who continue to make the perilous journey across the Mediterranean from northern Africa to European shores. Frontex, the European Union border agency, says the majority of people residing illegally in the EU arrived by plane with a valid travel visa and simply stayed on after their visa expired. But Frontex also estimates that at least 72,000 people illegally entered the EU via land and sea routes in 2012 -- and the actual figure may be much higher.
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Frontex: At least 72,000 illegally entered EU via land and sea routes in 2012
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51% of migrants entering illegally took an eastern Mediterranean route, says border agency
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Migrant crossings through central Mediterranean, including Lampedusa, are on the rise
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Frontex says majority of those living illegally in Europe arrived by plane with valid travel visa
The EU also said it is setting up a new border surveillance system and @placeholder task force to bolster its efforts and will review its asylum immigration policies next summer.