Iqbal Singha of India, said in November that areas patrolled by Undof had been heavily affected by the fighting.

WSJ: Syrian Rebels Abduct U.N. Soldiers

"In this case it is particularly bizarre because Undof are unarmed, " he said.

WSJ: Syrian Rebels Abduct U.N. Soldiers

Several videos emerged on Thursday, showing groups of between three and six peacekeepers from the United Nations Disengagement Observer Force (Undof).

BBC: Seized UN observers 'well treated' by Syrian rebels

The Syrian fighting had begun affecting the peacekeepers by late 2012, when the Undof commander complained of forces being caught in crossfire between the Syrian army and the rebels.

WSJ: Syrian Rebels Abduct U.N. Soldiers

The Syrian Foreign Ministry summoned Major-General Iqbal Singh Singha, the head of mission and force commander for United Nations Disengagement Observer Force (UNDOF) on the Golan Heights, to complain about the Israeli violation.

NPR: Syria Threatens Retaliation For Israeli Airstrike

Undof peacekeepers operate within a demilitarized buffer zone from which Israeli and Syrian forces are prohibited, and in outlying areas where government forces are permitted, in numbers that increase the further from the buffer zone.

WSJ: Syrian Rebels Abduct U.N. Soldiers