Via Times of Israel:

Since the beginning of the Syrian conflict in March 2011, between 2,000 and 5,500 foreign fighters, including up to 600 Europeans, have joined rebel forces in the fight against the Assad regime, a new study has found.

The International Center for the Study of Radicalization (ICSR) at King’s College London in the UK published its findings on Tuesday, citing over 450 Western and Arab sources and martyrdom notices on jihadi Internet forums.

Between “140 and 600 Europeans have gone to Syria since early 2011,” said researcher Aaron Y. Zelin, noting that up to 400 yet remain on the battlefield.

As many as 134 fighters from Britain have fought in Syria, according to the study, with 107 from the Netherlands, 92 from France and 85 from Belgium. The countries with the least fighters in Syria (1 apiece) are Albania, Austria, Bulgaria and Kosovo.

Other countries include Finland, Ireland, Sweden and Spain.

Most of the Dutch citizens estimated to be fighters have reportedly remained on the battlefield.

“As with previous conflicts, the picture is far from complete and will probably remain so for years to come,” said Zelin. “There is no ‘true census’ of foreign fighters, and publicly available sources are inevitably incomplete.”