MOSCOW (AFP) - A Russian traveller and photographer captured by Syrian rebels in the city of Aleppo in 2013 has been freed and returned home three years later, Russia's FSB security service said on Friday (Oct 14).

Konstantin Zhuravlev "has been returned to Russian soil" after being "abducted in northern Syria by an armed group and forcibly held for three years," the FSB said in a statement.

The Islamist group Liwa al-Tawhid seized Zhuravlev on Sept 30, 2013, in Syria's second city Aleppo, Russian news agencies reported at the time.

Liwa al-Tawhid was one of the most powerful factions in Aleppo province early in the uprising. It merged in 2013 with Ahrar al-Sham and Jaish al-Islam to form the Islamic Front, whose role in the conflict is now unclear.

Russia has been flying a bombing campaign in Syria in support of the regime of Bashar al-Assad for the past year.

Its airpower is currently backing up a fierce government assault on rebel-held eastern Aleppo that has sparked accusations from the West of potential war crimes.

Zhuravlev, who was 32 when captured, had hitchhiked from Siberia and entered Syria via Turkey.

He was thought to be travelling through Syria en route to the Sahara desert, where he planned to spend 21 days alone "face-to-face with the desert", according to Tass news agency.

Zhuravlev is a photographer and experienced traveller, who toured the world for 777 days between June 2010 and August 2012.

He was able to communicate with his mother via Skype in 2014 in footage aired on television, telling her that his captors had threatened to kill him unless the Russian government took action in his case.