The Italian government is blocking private rescue boats that it blames for encouraging human traffickers to launch unseaworthy boats loaded with migrants toward Europe.
But the aid groups deny having any link to smugglers in Libya or elsewhere, and say they are being forced to leave unattended the busy migrant sea transit route where deaths are mounting.
The Open Arms rescue ship completed a four-day journey to Barcelona, in northeastern Spain, after it saved 60 people Saturday from a rubber boat floating in waters north of Libya.
The migrants come from 14 different countries and include five women, a 9-year-old boy and four older teenagers, some of them unaccompanied. The Spanish aid group Proactiva Open Arms said they were generally in good health but some may have fuel burns.
The migrants were going through health checks and identification procedures. Authorities granted them a 30-day permit to apply for residence or asylum in the European Union. Many have relatives in Germany, Belgium and France.
According to the International Organization for Migration, more than 500 people have died trying to cross from Libya since the Aquarius, another charity rescue ship, was blocked from ports in Italy and Malta in early June. The 630 migrants were finally taken in by Spain and France.
Doctors Without Borders blamed the deaths on the European Union's inaction.