European officials have expressed increasing concern that militants from the Islamic State group, also known as ISIS, are posing as refugees to enter the European Union as those countries take in hundreds of thousands of refugees from Syria, Afghanistan and beyond, fleeing civil wars and violence. Media reports appear to have bolstered those fears, with Hungarian media reporting Tuesday that “Islamist terrorists, disguised as refugees, have showed up in Europe,” RT reported.

“Pictures were uploaded on various social networks to show that terrorists are now present in most European cities,” Hungarian M1 television reported. “Many, who are now illegal immigrants, fought alongside Islamic State before,” it added. It was unclear if the suspected militants had been arrested or detained.

Hungary has come under the spotlight in recent weeks for trying to stem the tide of refugees from the Middle East and North Africa, including by preventing them from boarding trains to Germany, Al Jazeera reported. At the same time, the possibility that militants and fighters could be scattered among humanitarian refugees presents a serious concern for European cities and countries.

The right-wing British politician Nigel Farage suggested Friday that the refugee crisis could endanger the country and continent, as there was “very genuine fear” that Islamic State militants could use the flow of refugees to their advantage and enter the European continent. “At the moment, the EU’s common asylum policy has absolutely no means whatsoever of checking anybody’s background, and I would say we must not allow our compassion to imperil our safety,” he said, the Telegraph reported.

Experts have suggested that European officials should be vigilant about possible militant threats but also remain aware that Europe’s borders have long been relatively porous, and refugees have sought asylum within them for years. “It’s a concern that people at borders are always going to have to be vigilant about and at the same time grapple with,” Sean Kay, a professor of international relations at Ohio Wesleyan University, told International Business Times Tuesday.

Others suggested that the outpouring of refugees represented a religious victory for the Islamic State group, which controls large swaths of Iraq and Syria. As the militant group drives Muslim and Christian men, women and children from their homes and out of their countries, “if all these refugees come to Europe or elsewhere, then Islamic State has won,” French Foreign Minister Laurent Fabius said Tuesday. He called for the Middle East to remain what he defined as “a region of diversity where there are Christians, Yazidis, etc.”

The Islamic state wants to target Kurds in the West, the latest IS magazine published last Wednesday reveals.

The IS called on Muslims living in the West who are not able to move to Islamic state hold territory, to attack enemies of the IS specifically naming the Kurdish forces that fight IS in Syria and Iraq.

“As for the Muslim who is unable to perform hijrah from dārul-kufr to the Khilāfah, then there is much opportunity for him to strike out against the kāfir enemies of the Islamic State,” the IS said in Dabiq 11.

“What prevents him [the Muslim in the West] from targeting the allies of the PKK [Kurdistan Workers Party] and Peshmerga in Europe and America,” the IS said in a call to Muslims in Europe.

The IS specifically mentioned two groups affiliated to the PKK in Germany and the Netherlands.

“(…) including the “Confederation of Kurdish Associations in Europe” (KON-KURD – based in Brussels) and the “International Kurdish Businessmen Union” (KAR-SAZ – based in Rotterdam), both of which are infamous for their financial support of the PKK?” the IS said in the article.

Europe proposed a military solution Thursday to stop smugglers carrying people across the Mediterranean and Aegean seas in overcrowded rubber dinghies, as thousands of refugees continued to risk their lives to cross from the Middle East and North Africa. Several European nations have pushed for a United Nations Security Council resolution that would allow European Union troops to board and search vessels — specifically on the popular route from Libya to Italy.

The draft resolution has not yet circulated among all 15 of the member states of the U.N. Security Council, and it is one of several solutions on the table to stem the flow of migration in Europe. Escalating conflicts — particularly in Syria and Eritrea — have pushed a rising number of civilians to flee their countries in search of safety in Europe, with many of them turning to smugglers to make the crossing.

In the last year, authorities have limited or entirely closed down certain routes and methods of transportation in an effort to limit illegal immigration. These initiatives have included limiting and regulating ferry traffic from Turkey to Greece — the route most often used by Syrian refugees, as Turkey shares a border with Syria and some of its Western ports are only a few miles from Greece, making it a close point of first entry to the EU.

The limitations placed on routes and boats has pushed desperate refugees to turn to smugglers who will take them on these dangerous sea crossings, often charging upward of 1,000 euros per person. The U.N. estimated that over 2,850 people have drowned while attempting to make these crossings.

The initial proposal to the Security Council suggested European troops conduct military operations off the coast of Libya. But Libyan authorities did not approve such a plan, and the revised proposal instead allowed for smuggler boats carrying refugees in international waters to be seized by European authorities.

In contrast with previous legislation, the new proposal would send refugees to Italy instead of back to Libya in order to determine each person’s refugee status and give him the appropriate rights if granted asylum.

“It’s our moral and legal duty to take those people to safety — which means north, not south,” said one diplomat, who spoke to the New York Times on the condition of anonymity, adding, “It would be for the Italians to work out which of them were refugees and which were not.”

Russia’s Foreign Ministry spokeswoman has accused the West of creating “strange hysteria” over Russian activities in Syria, saying that Moscow has been openly supplying weapons and sending military specialists to Syria for a long time.

The U.S. has expressed concern about signs of a Russian military build-up in Syria, including possible preparations for sending in troops.

Foreign Ministry spokeswoman Maria Zhakarova told journalists Wednesday that “Russia has never made a secret of its military-technical cooperation with Syria.” And she could “confirm and repeat once again that Russian military specialists are in Syria to help them master the weapons being supplied.”

President Vladimir Putin and other Russian officials also have confirmed in recent days that Russia has military experts in Syria to train its military on how to use Russian-supplied weapons.

Greece granted Russia the right to use its airspace for humanitarian flights to Syria on Aug. 31, TASS news agency quoted a Russian embassy official in Athens as saying on Wednesday.

The Russian agency added that the request covered the period from Sept. 1 to Sept. 24.

Separately, Russia’s Interfax news agency quoted a Russian embassy official in Tehran as saying Iran had approved all of Moscow’s requests on flights delivering humanitarian aid to Syria.