Italy's hard-line interior minister is reacting with anger after migrants rescued by a humanitarian ship landed on Italy's southern island of Lampedusa despite his explicit ban.

Matteo Salvini on Monday threatened charges against anyone who acted illegally to bring the 47 migrants to land. He said on Facebook if "there was a ploy to disembark the migrants, I will take action because that is aiding and abetting human trafficking."

The German aid group Sea-Watch said the remaining migrants on board their rescue ship were transferred to Lampedusa on Sunday evening with the cooperation of the Coast Guard and financial police. They were among 65 migrants rescued off the coast of Libya last week.

Sea-Watch said its vessel was too big to enter Lampedusa and had been ordered to another port on "probationary confiscation."