The Italian government on Tuesday threatened to shut humanitarian groups that operate migrant rescue ships in the Mediterranean out of the country's ports if they do not sign a "code of conduct.

Italy fears that the ships are making it too easy for smugglers to operate and that they act as an incentive for migrants who want to reach Europe. An Italian court has also suggested they collude with Libya-based smugglers, which the charities deny.

Italy's coast guard coordinates all rescues off the coast of Libya, which has been shattered by years of civil war. Almost 100,000 migrants have been brought to Italy this year, adding to the half a million brought over the three previous years.