Two French charities pulled another 81 migrants from the waters off Libya Sunday, bringing the number of those it rescued at sea since Friday to 211.
Doctors Without Borders and SOS Mediterranean jointly operate the Norwegian-flagged rescue ship Ocean Viking.
Most of those it picked up over the past three days are Sudanese men, including the 81 rescued from a flimsy rubber dinghy Sunday. Witnesses on the Ocean Viking say the men on the raft waved and cheered when they saw the ship approaching.
"We're the only ones in the area, the Libyan coast guard doesn't respond," SOS Mediterranean rescue coordinator Nicholas Romaniuk told an AFP reporter.
He said he expects more migrants leaving Libya over the next few days because of good weather and the Eid-ul-Adha holiday reducing the number of police patrolling the beaches.
Meanwhile, a Spanish aid group, Open Arms, said it has 160 migrants aboard its rescue ship, including three who need "specialized medical attention."
Open Arms founder Oscar Camps made another appeal Sunday to European governments for help, especially Italy, which is the closest safe port.
"Tenth day on board on a scorching Sunday in August. We have 160 reasons to carry on, 160 human beings who have the right to disembark at a safe port. Shame on you, Europe," Camps tweeted.
Italy's far-right Interior Minister Matteo Salvini said Italy is not "legally bound nor disposed to take in clandestine unidentified migrants."
Italy has complained it has done more than its share of allowing migrants to dock and wants other EU nations to do more to help.
Thousands of migrants from Africa try to reach EU shores from Libya every year. Those who are not rescued by charities are either left on unsafe boats to or picked up by the Libyan coast guard and returned to Libya, where they are housed in detention facilities.
Some of those facilities have been caught in the fighting between rival governments in Libya. A missile slammed into one detention building outside Tripoli in July, killing 53.