French police officers stop vehicles at the French-Italian border in Menton, Nov. 14, 2015. AFP/Boris Horvat

After Friday’s brutal attacks in Paris, it didn’t take long for an accusatory finger to be pointed at the hundreds of thousands of refugees pouring into Europe from embattled Iraq and Syria. At the G-20 summit in Turkey Sunday, Jean-Claude Juncker, president of the European Commission, announced that refugees who want to resettle in Europe will have to first pass through strict border controls, a rule that has not existed in mainland Europe for 20 years. Until last week, individuals with certain passports, including EU passports, were allowed by law to travel through what is known as the Schengen Area, comprising 26 European countries, where passport and border controls had been abolished.

Fears that the Islamic State group, commonly known as ISIS, had infiltrated the mass of refugees who are attempting to flee the militants, prompted the Polish government to back out of an earlier agreement to take in several thousand refugees. When Syrian passports were found near the bodies of two of the suspected attackers, one of which was held by a man who had registered as a refugee on the Greek island of Leros Oct. 3, the burden of blame grew heavier.

In his address to the world following the terrorist attacks, French President François Hollande declared a state of emergency and said all of the country’s borders would be closed, fearing other attackers could be making their way in. Slovenia, Austria and Germany also suspended their open borders system. Nicolas Sarkozy, the former president and leader of France’s main opposition party, declared he wanted a full renegotiation of the agreement’s rules. A restructuring of migration policy is the only plan that will keep the French safe, he said.

The implementation of border controls in a region with an open border policy for two decades has asylum seekers worried, especially those who cannot pay for a smuggler. Ahmed, a 15-year-old Syrian refugee from Aleppo who spoke to International Business Times Sunday, said he was en route to France when he heard about the attack and Hollande’s speech. The group he was with, he said, stopped in their tracks on the Belgian-French border and re-routed to the Netherlands.

“We were going to pass through to France, but didn’t know if there were going to be border controls already set up,” Ahmed said. “So we turned because we didn’t want to get caught by the police.”

Authorities throughout Europe who catch refugees crossing the border are legally required to collect their fingerprints and file them in a European database. Those refugees are then officially processed for asylum status in that country and are not allowed to seek asylum elsewhere. If the refugees move on to their intended final destination, they can be turned back.

More than ever that fingerprinting process is now the main concern for refugees trying to enter France. Although Syrians have paid thousands of dollars to smugglers to help them cross into Europe since the civil war began four years ago, those networks are now thriving with the uncertainty that's followed shifting entry policy.

Borders in France are open, but checkpoints are manned by policemen and doubts remain over whether the Schengen Agreement will hold and whether thousands of desperate refugees will still be able to make their way to northern Europe. Juncker condemned the attempt by some European countries to change the open door policy that has allowed unfettered travel across much of the continent for more than two decades, saying Europe is now known among refugees as an open, welcoming place where they can find safety away from ISIS.

“I try to make it crystal clear that we should not mix the different categories of people coming to Europe,” Juncker said. “The one who is responsible for the attacks in Paris cannot be put on an equal footing with real refugees, with asylum seekers and with displaced people. These are criminals and not refugees or asylum seekers. I would like to invite those in Europe who are trying to change the migration agenda we have adopted – I would like to invite them to be serious about this and not to give in to these basic reactions.”

Further changes to the Schengen Agreement could affect the safety of hundreds of thousands of refugees. This summer the citizens of Syria and Iraq faced unprecedented violence when ISIS stepped up its offenses in Iraq's western Anbar province and Aleppo, Syria. Russian military intervention in Syria has only fueled further bloodshed and spurred tens of thousands of people to travel by foot, boat and car to seek refuge in Europe.

Critics of the mass migration from the Middle East say the refugees include ISIS members and sympathizers. Others suggest that if the terrorists came into Europe after training with ISIS in Iraq and Syria, they could have used fake passports as police sources in France told Channel 4 News on Sunday. Even if the attackers were asylum seekers, shutting borders to refugees is not the way to go, Mia Bloom, an expert on terrorism and a professor at the Georgia State Department of Communication, told IBT.

“It’s like locking people in a burning building with their arsonists because we are afraid of the arsonists,” said Bloom.

“ISIS’ goal with these attacks is that they want the anti-immigrant sentiments to emerge [in Europe] so there is nowhere for these Syrian refugees to go. ISIS is trying to create the caliphate. Sunni Muslims running away from them, it just doesn’t compute.”

European Union ministers are set to discuss the possibility of officially amending the open border policy in the Schengen Agreement at a meeting this Friday. Until then, border checks will remain in place in France and thousands of refugees will be forced to either find new illegal crossings, or move on to a country with open borders.