Dozens of Swedish women have left the country to join violent extremist groups in Syria and the surrounding region, local media reported Friday.

Between 30 and 40 of the 150 confirmed cases of Swedes joining violent extremist groups such as the Islamic State are women, public broadcaster Swedish Radio reported.

"We also have unconfirmed information about around 100 other people who may have traveled," Simon Brynert, spokesman for the intelligence service Sapo, told daily newspaper Dagens Nyheter.

The Swedish nationals are typically recruited through social media, where women are encouraged to marry Jihadist fighters and support their cause.

"It is serious and troubling that several women have traveled to a conflict area and joined violent Islamist groups," Brynert said.

The Swedish intelligence service said it has no confirmed accounts of women actively participating in combat or combat training but said women join the groups to "engage in logistics and supporting activities."

Around 50 of the Jihadist travelers have returned to Sweden. The intelligence service estimates that 40 Swedes have been killed in Syria.