Suspected ISIS recruiter
Spanish police arrest an 18-year-old Moroccan woman in Gandia on Sept. 5, 2015, She is suspected of recruiting other women via the Internet to the Islamic State group. Jose Jordan/AFP/Getty Images

Recruiters for the Islamic State group, also known as ISIS or ISIL, apparently earn thousands of dollars if they can convert their peers to jihadis. ISIS pays its supporters up to $10,000 for each person they recruit to wage jihad in Iraq and Syria, U.N. experts told reporters Friday.

"We have heard … about situations where recruiters were paid from 2,000, 3,000 to 10,000 dollars depending on ... who was recruited," Elzbieta Karska, who chairs a United Nations group studying the issue, told a press conference in Brussels, according to Agence France-Presse. "If somebody was well educated like computer specialists or doctors, they were paid more,” the Polish human rights laywer said, adding the findings were preliminary.

Karska said the Islamic extremist group is utilizing social media and “informal networks of friends and family” to enlist new jihadis in Belgium, one of the main countries of origin for so-called foreign fighters. After a visit to Western European country, Karska and her colleagues learned from sources that 500 foreign fighters in Iraq and Syria came from Belgium, the highest number from a European Union member state.

"A significant degree of recruitment currently occurs through friends and family in Syria, who are also paid on the basis of the number of persons they recruit and on whether the recruits subsequently marry," Karska told a press conference Friday, according to AFP.

A recent confidential U.S. intelligence assessment indicated that nearly 30,000 foreign recruits from more than 100 countries have flocked to Syria and Iraq since 2011, many to join the ranks of the Islamic State group. The figure has doubled in the past 12 months, which shows that international efforts are not slowing the recruitment of new fighters, the New York Times reported.

“By now there is a ‘network effect’ where friends, family are bringing along other friends and family,” Daniel L. Byman, a counterterrorism expert who is a professor at Georgetown University in Washington, D.C., and a fellow at the Brookings Institution, told the New York Times in September.