International law enforcement agencies say smuggling networks cashing in on the huge flow of migrants into Europe had an estimated turnover last year of up to $6 billion.

The agencies say that the number of people trying to reach the European Union is expected to increase, with some 800,000 waiting in Libya to cross the Mediterranean. More than 1.2 million people applied for asylum in the EU last year.

A summary published Tuesday of a joint Europol and Interpol report also warns "there is an increased risk that foreign terrorist fighters may use migratory flows" to sneak into Europe. It notes that two extremists involved in the deadly rampage in Paris on Nov. 13 last year entered the EU through Greece as part of the influx of migrants from Syria.