Around 6,500 refugees and migrants were saved off the Libyan coast in 40 separate rescue missions by the Italian coastguard.
Monday's efforts for one of the largest influxes of refugees in a single day this year showed people wearing life jackets jumping off one of the boats and into the Mediterranean before swimming towards rescuers.
The refugees, believed to be mostly from Somalia and Eritrea, were on flimsy rubber dinghies that become highly unstable in high seas.
"The command centre coordinated 40 rescue operations" that included vessels from Italy, humanitarian organisations as well as the European Union's border agency Frontex, and "saved 6,500" migrants and refugees, the coastguard wrote on Twitter.
Five-day-old twins were was among those rescued and airlifted to an Italian hospital, according to Doctors Without Borders, which took part in the operations.
On Sunday, more than 1,100 people were rescued in the same area.
Data released on Friday by the International Organisation for Migration said more than 100,000 migrants and refugees had reached Italy by boat this year, many of them setting sail from Libya.
An estimated 2,726 men, women and children have died over the same period trying to make the journey, an increase of about 50 percent on the same period in 2015.
Italy has been on the frontline of Europe's refugee and migrant crisis for three years.
More than more than 400,000 have successfully made the voyage to Italy from North Africa since the beginning of 2014, fleeing violence and poverty.
According to AFP news agency, there are about a dozen vessels run by humanitarian groups that patrol the waters off the Libyan coast, but tensions in the zone have flared recently as rival factions battle to control migrant trafficking.