The collapse of the self-proclaimed "Islamic State" Caliphate in Syria and Iraq has led to increased efforts by extremists to recruit their members in Sub-Saharan Africa, which could trigger a new migration crisis in Europe.

This was warned yesterday by the director of the United Nations World Food Program, David Beasley, the Associated Press reported.

Many of the Syrian extremists fled to the Sahel region, Beasley said. In this belt of semi-arid lands, stretching from east to west in Africa, there are 500 million people.

According to Beasley, IS extremists are collaborating with other extremist groups to create "extraordinary problems" across the region.

The World Food Program Director warned European leaders that a possible Sahel conflict could cause a far greater migrant crisis than the Syrian war.