Moroccan authorities have internally relocated hundreds of migrants seeking to illegally reach Europe in recent weeks, a local official and rights groups said on Sunday. The migrants have been relocated from Morocco's north to the country's southern part, for fear that they will attempt to sneak into nearby Spain, the official, from the northern city of Tangier, said.

"Authorities deported some of them to the southern towns after they were arrested while they were attempting to sail in rubber boats towards the Spanish coast," he told dpa on condition of anonymity.

On Saturday, authorities in Tangier, some 250 kilometers north of the capital, Rabat, started a crackdown on migrants suspected of planning to illegally travel to Spain, local media reported.

At least 155 migrants were rounded up and being investigated before they are deported to the south, the media added.

The Moroccan Association for Human Rights, a nongovernmental organization (NGO), told dpa that authorities have relocated more than 600 migrants from the northern city of Nador since Tuesday.

Rights advocates have criticized the relocation of migrants, mostly natives of Sub-Saharan Africa. The Moroccan Association for Migrants' Integration, another NGO, called on the government to stop what it called "arbitrary detention and forced relocation" of migrants. "These are illegal measures that have no basis in the Moroccan law," the group added in a statement.