Italy helped rescue a total of more than 3,300 migrants trying to cross the Mediterranean on Friday, the country's coastguard has said.
In one operation, 17 bodies were found on three boats. Another 217 people who were on board were rescued.
The coastguard said distress calls were made from 17 different boats on Friday.
The International Organization for Migration (IOM) says at least 1,826 people have died trying to cross the Mediterranean so far in 2015.
It represents an almost 30-fold increase on the same period last year, the IOM says.
The Corriere della Serra newspaper said (in Italian) that most of the rescues on Friday took place close to the Libyan coast.
Irish, German and Belgian ships took part in the rescue, the newspaper said.
The UN estimates that at least 40,000 people tried to cross the Mediterranean between the start of the year and late April.
The rise has been attributed to chaos in Libya - the staging post for most crossings - as well as milder weather.
Many migrants are trying to escape conflict or poverty in countries such as Syria, Eritrea, Nigeria and Somalia.
On Thursday, the charity Medecins sans Frontieres reported that a 98-year-old Syrian man had been rescued from a boat, having travelled by sea from Egypt for 13 days. He was taken to Augusta in Sicily.
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