BRUZGI, BELARUS (NYTIMES) - After more than a week sleeping in a frigid encampment on the border between Belarus and Poland, and an abortive foray across the frontier repelled by pepper spray and police batons, Mr Mohammad Faraj gave up this month and retreated to a warm hotel in Minsk, the capital of Belarus.

Soon after, however, he watched with surprise and excitement a video report on Facebook claiming that Poland was about to open its border and urging all those who wanted to enter the European Union to gather at a petrol station near the encampment that the migrants had nicknamed "the jungle".

Mr Faraj, a 35-year-old ethnic Kurd from Iraq, rushed back to the squalid camp he had just left, travelling 305km (190 miles) from Minsk to the petrol station for the "border opening" that he had heard about on Facebook.

The Polish border, of course, remained tightly shut and he spent the next 10 days in what he described as "like something out of a horror movie".

The EU, offering robust support to Poland's hardline stand against migrants, has blamed the traumas of recent weeks on its eastern border on Belarus' authoritarian leader Alexander Lukashenko.

Belarusian authorities certainly have helped stoke the crisis, offering easy tourist visas to thousands of Iraqis and easing their way to the border with Poland.

But social media, particularly Facebook, have also given Mr Lukashenko a vital assist, as an unpredictable accelerant to the hopes and illusions of people who have fallen prey to the empty promises of profiteers and charlatans on the Internet.

Some were in it for money, promising to smuggle migrants across borders for hefty fees; some appeared to bask in the attention they received as online "influencers" for sharing information; others seemed motivated by a genuine desire to help people.

There has been no evidence to suggest a coordinated campaign by Mr Lukashenko to target migrants with fake information online.

Fake news on Facebook "poured mud on our heads and destroyed our lives", said Mr Faraj, who last week was moved from the border encampment along with 2,000 other denizens of "the jungle" to a giant warehouse nearby converted into a migrant holding centre.

Since July, activity on Facebook in Arabic and Kurdish related to migration to the EU through Belarus has been "skyrocketing", said Ms Monika Richter, head of research and analysis for Semantic Visions, an intelligence firm that tracked social media activity related to the crisis.

"Facebook exacerbated this humanitarian crisis and now you have all these people who were brought over and explicitly misled and ripped off," she said.

Researchers said smugglers openly shared their phone numbers and advertised their services on Facebook, including video testimonials from people said to have reached Germany successfully via Belarus and Poland.

In one post, a smuggler advertised "daily trips from Minsk to Germany with only a 20km walking distance". The journey, a writer warned in another post on Oct 19, is "not suitable for children due to the cold".

Another smuggler with the Facebook username "Visa Visa" pitched trips to Germany from Belarus through Poland and said the trip would take eight to 15 hours but added a warning: "Don't call if you are afraid."

By Friday, despite the bitter experience of so many promises on Facebook that turned out to be false, a ripple of excitement swept across despondent people huddled in the warehouse after reports on social media that it was still possible to get into Europe - for anyone willing to pay US$7,000 (S$9,558) to a guide who claimed to know an easy route across the Belarus-Poland frontier and through massed ranks of Polish soldiers and border guards on the other side.

Mr Rekar Hamid, a former maths teacher in Iraqi Kurdistan who had already paid about US$10,000 to travel agents in Iraq for a "package tour" that was supposed to get himself, his wife and young child to Europe but only got them locked up in a warehouse, scoffed at the latest offer as yet another scam.

"They keep saying the door is opening, but look where we all are now," he said, gesturing towards a mass of people huddled on the concrete floor.

Mr Musa Hama, another Kurd from Iraq confined to the warehouse, lamented that no amount of fact-checking would prevent people grasping at straws of hope provided on Facebook. "People are desperate so they believe anything," he said.

The stampede by migrants to Belarus in the hope of getting into the EU began earlier this year when the authoritarian former Soviet republic relaxed tightfisted visa policies for certain countries, notably Iraq.

This was ostensibly an effort to boost tourism at a time when most Westerners were staying away, following a crackdown by Mr Lukashenko in response to a contested presidential election.

Sensing a lucrative business opportunity, travel companies in Iraq's semi-autonomous Kurdistan Region started advertising on Facebook and other platforms about the availability of visas to Belarus. Smugglers used social media to pitch Belarus as an easy backdoor to Europe.

Since July, Semantic Visions has identified dozens of Facebook groups created to share information about migration routes and used by smugglers to advertise their services.

Facebook, now officially known as Meta after a corporate name change, said it prohibited material that facilitates or promotes human smuggling and has dedicated teams to monitor and detect material related to the crisis. It added that the company was working with law enforcement agencies and non-governmental organisations to counter the flood of fake news relating to migration.

"People-smuggling across international borders is illegal and ads, posts, pages or groups that provide, facilitate or coordinate this activity are not allowed on Facebook," the company said in an e-mail statement. "We remove this content as soon as we become aware of it."

But the events in Belarus have exposed how, even after Facebook experienced a similar abuse of its services during the European migration crisis in 2015, the company still struggles to keep banned material off its platform, especially in non-English languages.

"Facebook is not taking its responsibility seriously and as a direct consequence of that, we see desperate people in the cold, in the mud, in the forest in Belarus, in a desperate situation, all because they believe the misinformation that was provided to them through Facebook," said Mr Jeroen Lenaers, a member of the European Parliament from the Netherlands, who is a leader on the legislature's committee that handles migration issues.

It is unclear what steps, if any, Facebook has taken to deal with misleading and potentially dangerous information.