Across the globe, the number of foreign fighters traveling to Iraq and Syria continues to climb, but Russia and Central Asia have experienced the most dramatic change over the past year, with some estimates suggesting a 300 percent increase.

Russia, with an estimated 2,400 fighters, is now believed to be the third biggest supplier of foreign fighters to radical Islamist groups fighting in Iraq and Syria, according to new analysis from the Soufan Group, a security consulting firm based in New York.

In June 2014, it was estimated that Russia had around 800 foreign fighters in Iraq and Syria.

“Comparatively speaking, this increase is far more substantial proportionately than that seen in Western Europe over the same time span,” the Soufan Group says in a report it plans to release tomorrow. The Daily Beast obtained an early copy.

The only two countries who currently supply more fighters are Tunisia, with an estimated 6,000, and Saudi Arabia, with 2,500. Jordan also continues to rank among the top nationalities fighting with the so-called Islamic State or Jabhat al-Nusra, the al-Qaeda franchise, with somewhere between 2,000 and 2,500 Jordanians leaving home to fight in Iraq or Syria.

The majority of Russia’s foreign fighters is coming from the North Caucasus—Chechnya and Dagestan, areas with long histories of Islamic extremism.

“Local grievances have long been drivers of radicalization in the Caucasus, and as the strong centralized security apparatus of the Russian government limits the scope for operations at home, the Islamic State has offered an attractive alternative,” the Soufan Group report says.

But news investigations have also revealed that Russian authorities have encouraged local jihadists to travel to Syria. The logic being: better terrorists fight abroad than make trouble in Russia. According to a report in Novaya Gazeta, Russia’s domestic intelligence agency—the Federal Security Service or FSB—facilitated the travel of Russian fighters headed to Syria.

With the terrorist attacks in Paris carried out by French and Belgians who’d traveled to Syria to fight, and with the Islamic State claiming responsibility for the bombing of a Russian airliner in Egypt in October, Russia may be rethinking its strategy to export local fighters. Rather than guaranteeing more safety at home, Russia could be sending men and women off to collect valuable combat skills on the battlefield that can be brought back home to carry out attacks.

Addressing the threat in October, Russian President Vladimir Putin said a task force would be established to strengthen the borders of former Soviet republic states, who have also seen its foreign fighter numbers quickly climb over the last year. The Soufan Group has identified credible reports of foreign fighters in Syria from 12 of the 15 former Soviet states.

Approximately 2,000 militant fighters hail from Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan, according to the report.

Putin said between 5,000 to 7,000 people from Russia and the former Soviet states had joined the Islamic State. The Soufan Group report says that number is likely closer to 4,700. Either way, an alarming number of people are leaving the region to join the Islamic State, and did so before Russia began its bombing campaign in September against groups that oppose Syrian President Bashar Assad.

It is too soon to tell what effect Russia’s more aggressive approach in Syria could have on its own population. Over the past 18 months, recruits from North America have not escalated dramatically, despite the anti-ISIS bombing campaign led by the United States.

“This suggests that the motivation for people to join violent extremist groups in Syria and Iraq remains more personal than political,” the Soufan Group report says. “A search for belonging, purpose, adventure, and friendship, appear to remain the main reasons for people to join the Islamic State, just as they remain the least addressed issues in the international fight against terrorism.”

Just 18 months ago, the number of foreign fighters in Syria was believed to be somewhere between 12,000 and 15,000. Now, that number appears to have doubled.

Through its own investigation, the Soufan Group found that in total between 27,000 and 31,000 people have traveled to Syria and Iraq to join the Islamic State and other violent extremist groups from at least 86 countries.

This is line with a recent U.S. intelligence assessment that estimates nearly 30,000 foreign fighters have traveled to Iraq and Syria from more than 100 countries since 2011.

Western European countries have seen its foreign fighter numbers double over the last year, jumping from 2,500 in June 2014 to roughly 5,000 today. France, the United Kingdom, Germany and Belgium contribute the biggest numbers to this tally, making up almost 3,700 of the total.

As for fighters traveling from the United States, FBI Director James Comey has said that approximately 250 Americans have traveled or attempted to travel to Syria. In 2014, that number was closer to 70.

“There are no significant patterns of locally based recruitment in the Americas—nor recruitment hot spots—as seen in Europe and the former Soviet republics,” the Soufan Group report says.