ROME - Italian police have arrested 16 people suspected of trafficking migrants across the Mediterranean from Libya after a week in which thousands were rescued and hundreds drowned trying to make the journey.

As Europe’s worst migration crisis since World War Two continues, more than 2,500 people are thought to have died this year after being packed into rickety boats by traffickers.

Police in Catania, Sicily, said in a statement on Tuesday they had detained 16 men who were rescued in international waters along with hundreds of migrants and brought to the port city on May 28.

On arrival, testimony from the migrants helped police to identify a Gambian man believed to have captained one of the boats from Libya and 15 others who had brought fuel, looked after the engine and supervised the migrants during the journey.

The suspects arrived in Catania with more than 860 others who had been rescued in five different operations, police told a news conference.

Most of the migrants who arrive in Italy looking for a better life in Europe come from sub-Saharan Africa via Libya, where criminal gangs have taken advantage of the breakdown of order to set up a lucrative trafficking business.

The migrants arriving in Catania said they had been taken to a site near the western Libyan cities of Sabratha and Zuwarah, where they stayed for up to 45 days while the traffickers kept watch over them and fed them once a day.

They were then charged the equivalent of 500-1,000 euros ($557-$1,115) for the journey. None of the migrants were given life jackets, but all the suspected traffickers wore them.

Police suspect the group had contacts in Sicily to help organise the next phase of the migrants’ journey. Most people who come to southern Italy want to head to stronger economies in northern Europe where they expect more opportunities.