Arab citizen of Umm al-Fahm, home of Israel's first convicted ISIS terrorist, nabbed in an unconventional investigation.

A 22-year-old Arab citizen of Israel and resident of Umm al-Fahm, located in the "triangle" region of northern Israel which is home to over 300,000 Arab citizens, was indicted on Thursday for supporting the brutal Islamic State (ISIS) terrorist organization.

The indictment was submitted against Jamal Suleiman Abu Ra'ad, who was found thanks to an unusual investigative method - looking at his Facebook page.

Ra'ad had posted and shared posts on the social media site supporting the ruthless jihadist group, which is outlawed in Israel ever since Defense Minister Moshe Ya'alon (Likud) early last September declared it to be an illegal organization.

He was arrested in a joint operation between the Israel Security Agency (ISA) and Yamar, the police's central investigative unit, after they received information that he was a supporter of ISIS.

"We will do all we can to eradicate the dangerous and illegal phenomenon of Israeli citizens supporting the murderous terrorist organization Daesh, due to the danger it presents to the security of the state of Israel," read an ISA statement using the Arabic acronym for ISIS.

Umm al-Fahm appears to be something of a breeding ground for ISIS jihadists; late last September a 23-year-old resident of the city became the first Israeli citizen to be convicted for joining ISIS.

Since then many other Arab citizens have followed suit, with no fewer than four Israeli Arabs having died fighting for ISIS in Syria and Iraq.

The group has also made inroads to Judea, Samaria and Gaza, with an ISIS cell busted in Hevron last November. By last October security sources revealed that already no fewer than 30 Arab citizens of Israel had joined ISIS.

The group has also threatened to replace Hamas and the Palestinian Authority (PA), and claimed launching an attack on Hamas earlier this month.