Frustrated migrants from countries such as Morocco, Algeria and Pakistan have tried to storm the Greek-Macedonian border, tearing down part of a barbed wire barrier and demanding to be allowed to continue their journey to northern Europe. A few ran across into Macedonia but were quickly detained by police. Slovenia, a member of Europe's Schengen zone of passport-free travel, declared it would only grant passage to those fleeing conflict in Syria, Iraq and Afghanistan, and that all others deemed "economic migrants" would be sent back.