The crew of the rescue ship "Ocean Viking" rescued 572 migrants from the Mediterranean within a few days.
The European organization SOS Méditerranée announced on Monday that a “large wooden boat” was in distress off the Libyan coast.
According to the information, it was the sixth mission since Thursday.
According to SOS Méditerranée, 369 migrants were picked up from the last boat alone in a five-hour rescue operation, including 110 unaccompanied minors as well as an infant and two other small children.
The people come from, among others, Egypt, Bangladesh and Eritrea.
Before that, the “Ocean Viking” had taken in 71 migrants off Malta.
They were reportedly in an overloaded wooden boat that had started three days earlier from the Libyan coast.
Four people had to be taken off the boat on stretcher because of their weakened condition.
The ship is full
The "Ocean Viking" is now "pretty full", said a spokeswoman for SOS Méditerranée.
In such cases, the private sea rescuers usually ask the authorities in Malta and Italy to land in a safe harbor in order to bring the people ashore.
In Italy, some of the missions are politically controversial.
Meanwhile, the United Nations refugee agency reported on Monday night of around 250 people who were "rescued" or "intercepted" by the Libyan coast guard and brought back to the civil war country.
Non-governmental organizations criticize this because the people in Libya are often threatened with violence.
According to the International Organization for Migration, 886 migrants have already died in the dangerous crossing over the Mediterranean since the beginning of the year.
Last year the death toll was more than 1200. Experts assume a high number of unreported cases.
SOS Méditerranée claims to have saved more than 30,000 people since February 2016.