Eighteen people have been found dead on board a crowded boat travelling from North Africa to the Italian island of Lampedusa.
The would-be migrants all apparently suffocated.
A nineteenth man died during his transfer to the island.
Two other people found in a critical condition on the boat were taken to hospital in Palermo.
The vessel was carrying more than 600 people, mainly Eritreans, Somalis, Afghans and Syrians. Many of them needed medical aid.
Around 500 Moroccans on board the ship will be repatriated.
According to the Italian navy, hundreds of new migrants arrived on Friday in Italian territorial waters on Friday. The navy said it collected at least 1,400 people travelling from Libya the previous day.
Authorities say more than 60,000 migrants have already landed in southern Italy this year, and that the record of 63,000 set in 2011 is likely to be broken.