Syrian rebels capture 20 U.N. observers [VIDEO]

Syrian rebels held 20 U.N. officials who monitor the Israel-Syria ceasefire, the first time such officials have been targeted in the insurgency.

The members of the U.N. Disengagement Observer Force were reviewing damage at an observation post that had been evacuated over the weekend when they were captured and held by insurgents, the New York Times reported.

A group called Martyrs of Yarmook claimed responsibility in a video posted on YouTube and demanded a withdrawal of Syrian government forces from the area.

The U.N. Security Council called for the release of the observers, Israel Radio reported.

Israel captured the Golan Heights from Syria in the 1967 Six-Day War.

The U.N. observer force has monitored a ceasefire since it was brokered in 1974 by the United States.

The border has remained peaceful since then, although since the insurgency was launched in 2011, there have been a number of incidents of cross-border fire.