A London-based violence monitoring group reports that Syrian forces and rebels have been struggling for control of the Syrian village of Jamla, close to where the UN peacekeepers were detained.
A statement on the group's website said:
The Syrian Observatory received a footage reporting that rebel fighters will not released [release the UN personnel] until regular forces withdraw from the area.
The Jamla village and its surrounding areas have witnessed violent clashes in the past couple of days.
Rebel fighters from several factions took hold of the Mortar division and several checkpoints in Jamla.
More top news
An Australian grandfather has been hailed for his "fantastic survival skills" after keeping himself alive in the bush by eating ants.
A man who was never expected to be able to get out of a wheelchair has shared his first dance with his wife.
Sitting down is no worse for you than standing up as long as you take regular exercise, according to a study.