Several migrants blocked traffic at the Greece-Macedonia border on Monday, demanding passage to Western Europe.

Reuters reports hundreds of men and women from countries such as Morocco, Iran and Pakistan stood together in protest over new polices that denied certain migrants entry into Balkan nations.

Some of the protesters called for a hunger strike, while others issued a vow of silence.

One man, a 34-year-old electrical engineer from Iran, sewed his lips together with nylon and sat in front of a row of Macedonian riot police.

"To any free country in the world," said the engineer, Hamid, when asked where he wanted to go by reporters. "I cannot go back [to Iran]. I will be hanged."

Despite its status as a member of Europe's Schengen zone of passport-free travel, Slovenia announced last week that it would only continue to accept migrants from the war-torn countries of Syria, Iraq and Afghanistan. Other travelers -- labeled "economic migrants" -- would be sent back.

Several other countries along the route, including Croatia, Serbia and Macedonia, quickly followed suit.

The policy affects thousands of migrants who have traveled along the Balkan Peninsula after arriving by boat to Greece, attempting to reach Western nations such as Germany and Sweden. A number of human rights groups have criticized the policy.

"To classify a whole nation as economic migrants is not a principle recognized in international law," said Rados Djurovic, director of the Belgrade-based Asylum Protection Center, according to Reuters. "We risk violating human rights and asylum law."

Debate has raged among many Western nations concerning the heavy influx of migrants and refugees into Europe. Some are concerned about the possibility of terrorists infiltrating their countries, particularly in light of the recent terror attacks in Paris that left 129 people dead. While most of the Paris assailants were French or Belgian nationals, two of the suicide bombers arrived on the same route many migrants take across the Balkans.