Morocco on Wednesday announced a new immigration policy, pledging to review cases according to specific criteria, following sharp criticism over its treatment of sub-Saharan migrants.

The announcement comes three days after Morocco's National Human Rights Council (CNDH) issued a report calling for "a radically new asylum and immigration policy," to which King Mohamed VI responded by admitting "legitimate concerns".

Those concerns have been rising during the past few months among the estimated 20,000 sub-Saharans residing in Morocco, amid reports of racist violence.

In late July, a Congolese university professor living in Tangiers reportedly died after a police officer pushed him from a bus deporting him to the Algerian border, and in August a Senegalese man was stabbed to death at the central bus station in Rabat.

Under the government's new plan, the interior, foreign and justice ministries will establish procedures in the coming days for reviewing the situation of unregistered foreigners "on a case by case basis and according to specific criteria".

The government also pledged to strengthen institutional frameworks for processing requests for asylum "in line with international standards and respectful of the kingdom's commitments to promote and protect human rights".

But it vowed to continue the fight against human trafficking, and called on its European partners in particular "to demonstrate a concrete commitment" to supporting the implementation of the new policy.

Morocco is the closest African country to mainland Europe, separated by the Strait of Gibraltar and just 15 kilometres (nine miles) from Spain at its narrowest point, making it one of the key smuggling routes for illegal migrants crossing into Europe.

Thousands of illegal African migrants regularly attempt to cross from Morocco into Spain on makeshift boats each year, making the North African country an ally of the European Union in tackling the problem.

Before the government's new policy announcement, the EU representative in Morocco, Rupert Joy, hailed the CNDH's recommendations for "recognising the violations of migrants' rights, which have worried us for a long time," and for proposing "a fairer and more efficient" policy.

Several months ago, medical aid group Doctors Without Borders raised the alarm over increased violence by the authorities against illegal migrants, and announced it was closing its projects in Morocco in protest.

In a report to be presented to the UN Human Rights Council this week, GADEM, a Moroccan NGO supporting illegal immigrants, charged that successive governments in the past decade have "pursued the same repressive policies in... 'managing the flow of migrants.'"

"This violence is far from over, as witnessed by the tragedies of recent month, which have been particularly violent for migrants in Morocco," it added.

Contacted by AFP, the head of migration and border control at the interior ministry, Khalid Zerouali, insisted the authorities' main objective was to "protect citizens", adding that their border "security strategy is directed against criminal networks" and no one else.