Six Syrian refugees, including three children, were found dead on a migrant boat that arrived on Monday in the Sicilian port of Pozzallo, the United Nations refugee agency (UNHCR) said.
"They died of thirst, hunger and severe burns. This is unacceptable," the UNHCR's representative to Italy, Chiara Cardoletti, wrote on Twitter. "Strengthening rescue at sea is the only way to prevent these tragedies."
The UNHCR said in a statement the dead were among a group of 26 people who had been on the boat for days. It added that two of the dead children were aged 1 or 2, while the other child was 12. The bodies of a mother and grandmother were also recovered.
Another woman and her daughter were airlifted from the boat to a hospital on the nearby island of Malta on Sunday, the UNHCR said.
The UN agency said more than 1,200 people have died or vanished this year while trying to cross the Mediterranean and reach Europe.