The Italian Navy says it rescued more than 300 migrants off the coast of the Sicilian island of Lampedusa.
The navy said in a statement it decided to intercept one dinghy - carrying about 100 people - after the weather deteriorated on Wednesday.
Another group of migrants were rescued later that evening.
The group was transferred onto a navy ship - and will be transported to a port in Sicily on Thursday.
Hundreds of people have died in October trying to reach Lampedusa by boat from North Africa.
More than 32,000 migrants from Africa and the Middle East have arrived in Italy and Malta so far this year - prompting Italy to step up its patrols to spot migrant boats in the Mediterranean.
Italy plans to request reform of European asylum policy - to handle the crisis.