On April 6, Ahlul Hakk, a Russian-speaking pro-IS group on the VKontakte social network issued an emergency announcement.
It is still possible to cross into Syria from Turkey, the message said, despite rumors that the Turkish authorities have closed the border.
"Recently, rumors have been spreading that the border between Syria and Turkey is closed and that it is not possible to make Hijra [an Arabic term used by IS to mean immigration to the lands under its control], and that there is a chain of tanks along [the border] and that allegedly Muslims are spending months in Istanbul in standby mode," read the message, which said that it was intended for "brothers and sisters from the caliphate [the term used by IS for the lands under its control] first and foremost, and to those who are outside its borders."
The message said that the rumors that the border crossings were closed were "fundamentally incorrect," as the border had never been open in the first place, so the only way to cross into Syria was illegally using "guides and loopholes."
Ahlul Hakk added that, even though there really are tanks on the border, "even these tanks cannot stop the flow of the muhajireen [immigrants] by the grace of God."
The message comes amid signs of increased efforts by IS -- including Russian-speaking militants -- to attract new recruits to come to Syria, and increased efforts by Turkey to crack down on those trying to cross the Turkish border into Syria illegally.
In the past week, authorities in Turkey say they have arrested seven Russian nationals who tried to cross the border into Syria to join the Islamic State (IS) militant group.
Two Russians were arrested on April 4, and five more were detained on April 7, according to the reports, which cited Turkish security authorities in Gaziantep province.
The reports did not provide the names of those arrested or any further details, such as where in Russia the suspects had come from.
The arrests of the seven Russian nationals are part of increased efforts by Turkey to prevent foreign fighters from crossing into Syria and joining IS and other militant groups.
Alongside the crackdown, Turkish news reports also say that there has also been an increased number of potential militants trying to cross the border.
In addition to the seven Russians, officials from Gazantiep Province said that suspects from Switzerland, Kosovo, Syria, and Tajikistan were detained in southern Turkey this week.
The Turkish Armed Forces said that they had arrested 15 Chinese nationals and 15 Syrians who were all trying to cross into Syria on April 5, according to Turkey's Daily Sabah news website.
In March, Turkey said it had deported several Russians, a Chechen, and a Tajik, who had been among tens of foreign citizens trying to cross into Syria to join militant groups.
The reports about an increased number of potential militants trying to cross into Syria, and the news that groups of Russians are among those attempting to join IS, come amid evidence that IS has stepped up recruitment of Russian-speaking men and women.
Despite frequent attempts to shut them down, IS maintains an extensive, unofficial Russian-language network on social media, including on Russia's VKontakte and Odnoklassniki social-networking sites, as well as on Facebook and Twitter. That network comprises accounts run by individual militants, IS sympathizers, as well as small media groups whose task is to publish IS-related news and material preaching IS's version of Islam.
Via this network, Russian-speaking militants in IS -- who are mostly from the North Caucasus -- have put out calls for both men and women to travel to Syria to join the group as well as a how-to guide advising potential IS recruits on how to travel from the Russian Federation to Syria.
The emergency announcement by the Russian-language pro-IS group Ahlul Hakk on VKontakte insisting that Turkey's illegal border crossings are still open suggests that news and rumors of the Turkish crackdown could have deterred potential recruits from trying to travel to Syria.
Ahlul Hakk even went so far as to accuse those Russian-speaking militants who are passing on rumors about difficulties crossing the border of "spreading fitna [dissent]."
"Stop scaring the muhajireen [immigrants]," Ahlul Hakk added. "Believe me, they have enough emotions and fears as it is. And I ask those who hear these rumors to cut them off at the root."
-- Joanna Paraszczuk