A spokesperson for Säpo told Radio Sweden that around 30 men have travelled from Sweden to Syria to train or fight with al-Qaeda-inspired groups.
That is the same figure that Säpo released before the summer, but Per Gudmundson, a columnist for the newspaper Svenska Dagbladet who blogs about international terrorism, tells Radio Sweden that the number could be even higher now.
"One person I have followed travelled to Syria as late as July," Gudmundson says.
He has tracked people who go abroad to join terrorist groups and claims he knows of at least 15 people who have traveled from Sweden to Syria to join resistance groups fighting Bashar al-Assad's regime.
Only one of those 15 people are of Syrian origin, says Gudmundson.
"A third have roots in Lebanon and some are Palestinians from Lebanon. But there are also individuals who were born in the Philippines and Morocco. All of them have lived in Sweden, but not all are Swedish citizens," says Gudmundson.
What the 15 also have in common is that they have fought against the Assad-regime and several have joined Jihadist groups, like Jabhat al-Nusra. Since Islamic terrorist groups have identified Sweden as a legitimate target, Säpo has expressed concern about these individuals returning to Sweden and inspiring terrorist actions here.
When Säpo released its report in April, its chief analyst, Jonathan Peste, told Swedish Radio News that a number of those who return from these kinds of trips do continue with terrorist activity in Sweden or elsewhere.
"Returnees have been involved in several of the serious attacks that have been planned or carried out," said Peste. According to Gudmundson's sources at least one, but possibly more, of the 15 individuals he has tracked have returned to Sweden but some were killed abroad.
"Eight have died as a consequence of the Syrian civil war, but one died in combat in Lebanon," says Gudmundson.