An Italian coastguard ship with around 522 migrants on board arrived at the Sicilian port of Pozzallo on Tuesday night. A number of the migrants had been rescued by the US Navy off Libya last week.
The Italian coastguard vessel "Diciotti" docked at Pozzallo in Sicily on Tuesday evening.
The UN refugee agency, UNHCR, was at the scene, along with Italian authorities and humanitarian organizations.
The migrants had been rescued in a number of separate operations. Forty-two had been rescued from the sea and needed urgent medical care and psychological support, the UNHCR said.
Several arrived extremely dehydrated and were taken into care by the Italian Red Cross.
The migrants arriving in Pozzallo included a group of around 40 people rescued from a vessel in distress off the coast of Libya last Tuesday by the US navy ship "Trenton", which transferred them to the "Diciotti".
The US Navy had reported it had seen 12 more bodies in the water but was unable to locate them during a search.
Another, nearby ship from the NGO "Sea Watch" had offered to take the migrants to Italy, but Italian authorities refused.
NGO rescue ships banned
Last week, the new Italian government banned the French NGO-operated ship "Aquarius", with more than 600 migrants on board, from docking in Italy.
The Italian interior minister, Matteo Salvini, said that in future, no NGO migrant rescue ship would be allowed to unload its "human cargo" in Italian ports.
Salvini accuses charities of being complicit with human smugglers in Libya.
"These people should know that Italy no longer wants to be any part of this business of clandestine immigration and they will have to look for other ports to go to," Salvini said at the weekend.
However, on Tuesday, an Italian court dropped a case in which two NGOs, including "Sea Watch", were accused of having links with human smugglers and facilitating immigration to Italy.