UN troops Golan Heights
A member of the U.N. Disengagement Observer Force (UNDOF) keeps watch of the Syrian side of the Quneitra crossing from an observation post in the Golan Heights August 28, 2014. REUTERS/Ronen Zvulun

The Syrian Army fought with Islamist rebels, including the Al-Nusra Front, in the Golan Heights Monday, escalating the violence in an area that has already experienced intense battles in the last week. The fighting broke just days after 44 Fiji peacekeepers were kidnapped and detained by Al-Nusra, which said it took the peacekeepers because the United Nations was protecting Israel.

Dozens of other blue helmeted peacekeepers from the Philippines escaped capture. The United Nations has said it does not know exactly where the peacekeepers are being held.

The fighting in the Golan Heights has escalated in recent weeks as rebels, mostly those fighting under the umbrella of Al-Nusra, have moved their operations closer to Israel. Last week, the rebel group took over the Quneitra border crossing, 45 miles southwest of the Syrian capital Damascus.

Since the rebels seized the border crossing, the Syrian military has been trying to regain control. Monday's fighting was the biggest push by the Syrian military to recapture the border crossing.

The Syrian Observatory for Human Rights, a monitoring group in London that keeps track of the violence in Syria, said Syrian soldiers and rebels had both died in the fighting. Al-Nusra's aim appeared to be "to end once and for all the regime's presence in the area and it also appears that the goal is to expel the international observers," Rami Abdelrahman, founder of the human rights group, told Reuters.