In countries like the U.S., Canada and Britain, potential recruits must find a jihadi mentor, which can be done online or through ISIS supporters in their local communities, according to Imam Syed Soharwardy, founder of the Islamic Supreme Council of Canada.

"I cannot believe that there is no one from ISIS on the ground here in Canada or the U.S. or Europe. They are now recruiting, so they are absolutely here," he told IBTimes. "IS people, those who are very rigid fanatics, they do live in this country, they do recruit. They do facilitate in recruitment."

The mentor-recruit relationship often begins through religious seminars, community activities or classes that might look normal to the average Westerner, Soharwardy said. Of the five known foreign fighters in Syria from Calgary, Alberta, three attended the same mosque, Soharwardy said.

It's important for recruits to mention the "right mosques" and to choose the right mentor.

IBTimes