At least 400 migrants trying to reach Europe from Libya were killed after their boat capsized, it emerged tonight. It was also claimed the body of one migrant, who died on another boat making the perilous trip from North Africa to Italy, was tossed overboard by a trafficker to circling sharks. The stories emerged after more than 8,000 migrants took advantage of calm weather to cross the Mediterranean over the past weekend. Scroll down for video . Rescued: The Italian coast guard involved in a operation to rescue migrants off the coast of Sicily on April 12 . Treatment: A refugee is stretchered off an Italian coast guard vessel in Palermo harbour, Italy on April 14 . A pregnant woman is helped off a boat at the Sicilian Porto Empedocle harbor on Monday. Italy's Coast Guard helped save 144 migrants Monday from a capsized boat in the waters off Libya . A Red Cross volunteer carries a baby wrapped in a blanket after migrants disembarked at the Sicilian Porto Empedocle harbor Italy on Monday . Charity Save the Children said the capsized boat, carrying about 550 people, flipped over around 24 hours after leaving the Libyan coast. About 150 survivors – mostly from sub-Saharan Africa – were rescued and brought to an Italian port on Monday. Before the weekend, more than 500 migrants had already died crossing the Mediterranean so far this year. This number is a sharp rise from just 47 in the same period of 2014, said the Geneva-based International Organisation for Migration. More than 170,000 migrants arrived in Italy last year after being packed on to boats by people smugglers. Yesterday, it was alleged that a trafficker on one boat threw a migrant overboard after he died from asphyxiation in the hold of the vessel. Witnesses said his body was attacked by sharks who had been following the boat. The suspected people smuggler, from Guinea, was arrested in Sicily after being rescued along with his 110 passengers, and it is thought he will also face manslaughter charges. In February, more than 300 people drowned while attempting the crossing in cold weather and rough seas. Saved: Rescued migrants onboard an Italian Finance Guard boat in Porto Empedocle, Sicily on April 12 . More than 170,000 migrants arrived in Italy last year after being packed on to boats by people smugglers . Calm weather: Migrants on a coast guard boat arrive at the Sicilian Porto Empedocle harbor, Italy on Monday . The Italian coast guard taking part in a rescue operation off the coast of Sicily on April 12. More than 8,000 migrants took advantage of calm weather to cross the Mediterranean over the past weekend . The number of migrant boats trying to reach the EU from Africa has risen in recent weeks as fine weather makes the route safer. The total rescued since Friday has now reached 8,480, from more than 40 boats. The Italian coast guard, navy ships and merchant vessels delivered migrants rescued from the boats to Italian ports throughout yesterday. A pregnant woman on board one Italian navy ship died during the journey to shore, and another pregnant migrant from Eritrea gave birth. Meanwhile, the EU’s Frontex border agency said traffickers trying to recover a boat had fired shots into the air to warn away the coastguard – sparking concerns for the safety of rescue workers and migrants. Save the Children and other humanitarian groups have called for the EU to bolster its rescue operations before the number of boats soars in summer, as it usually does. The Italian coast guard said Monday it recovered nine bodies after a boat carrying more than 150 migrants sank off the coast Libya . The number of migrant boats trying to reach the EU from Africa has risen in recent weeks as fine weather makes the route safer. The total rescued since Friday has now reached 8,480, from more than 40 boats . Migrants arrive at the Sicilian Porto Empedocle harbor, Italy on Monday. The total rescued since Friday has now reached 8,480, from more than 40 boats . A migrant is wheeled to hospital in Gwardamangia in Malta after being flown to the island. The woman is believed to be Somali . Italy, which handles the largest number of migrant arrivals in the EU, has become increasingly alarmed about the breakdown of law and order in Libya, which is home to two rival governments, loosely aligned militia forces and a growing militant Islamist movement. Giovanna Di Benedetto, a Save the Children official who assisted the new arrivals, told The Times: ‘A 17-year-old Nigerian whose brother was killed by Muslim fundamentalists told me he was tortured with electric shocks by traffickers because he didn’t have money to travel. Many are now talking about fleeing fundamentalists.’ Dimitris Avramopoulos, the EU’s commissioner for migration, said Europe must adapt to deal with the rising numbers of migrants. ‘The unprecedented influx of migrants at our borders, and in particular refugees, is unfortunately the new norm,’ he said in Brussels. More than 280,000 people entered the EU illegally last year. Many travelled from Syria, Eritrea and Somalia to Libya, and then made the perilous journey across the sea to Italy.
Around 400 migrants trying to reach Europe died when their boat capsized .
Body of one migrant on another vessel was thrown overboard to sharks .
Stories emerged after more than 8,000 crossed Mediterranean at weekend .