The Austrian government said Thursday that it would withdraw all of its peacekeepers from the United Nations monitoring force in the Golan Heights, on the Syrian-Israeli border, following clashes at a border post between Syrian rebels and government forces.

Austrians account for some 380 of the 1,100-strong UN force monitoring a ceasefire between Syria and Israel and their departure will deal a serious blow to the mission.

Syrian rebels and forces loyal to President Bashar Assad battled for control of the only border crossing to Israel on Thursday morning. Rebels launched their offensive on Quneitra early in the morning and seized it shortly after; IDF soldiers positioned in lookout towers around noon said Assad's forces had regained control of the crossing, amidst heavy fighting.

The rarely used crossing, in a UN-patrolled demilitarized zone on the Golan Heights, is the only transit point between Syrian and Israeli disengagement lines set in 1974. The Britain-based Syrian Observatory for Human Rights said this was the first time that rebels had seized the crossing.

The head the United Nations Disengagement Observer Force (UNDOF) confirmed that there had been incidents on the Syrian-Israeli border, but would not confirm if and by whom the crossing had been captured.

"Yes there was shooting," Herve Ladsous told reporters during a visit to Paris. "We are following events in the Golan Heights, which is a very sensitive region, with particularly close attention," he added.

Ladsous said the UNDOF had taken measures to ensure the safety of its personnel but stressed that its involvement was not called into doubt by the incidents. He added that the region had been "extremely confrontational" in the past year.

"We are doing everything we can to reduce risks. We have closed posts that were too exposed, reinforced our equipment and vehicles, and our activities are more static," he said.

Israel's Ch. 10 meanwile reported that a Filipino soldier was wounded by shrapnel during the morning battles.

Eyewitnesses in Quneitra reported heavy exchange of fire and smoke rising from the area. The crossing on the Syrian side of the border was badly damaged, they said.

Quneitra is less important than other border crossings, a source in the Syrian opposition told Haaretz. "The crossing may have symbolic [significance], but it doesn't have a strategic value because it does not function as a line for logistical support," he said.

The withdrawal of Austrian troops from the UN monitoring force on the Golan Heights will affect the operational capacity of the mission observing a decades-old ceasefire between Syria and Israel, a UN peacekeeping spokeswoman said on Thursday.

"Austria has been a backbone of the mission and their withdrawal will impact the mission's operational capacity," said UN spokeswoman Josephine Guerrero. "We are in discussions with them about timing, and with other troop-contributing countries to provide replacement troops."

Israel is worried that the Golan, which it captured from Syria in 1967, will become a springboard for attacks on Israelis by jihadi fighters, who are taking part in the armed struggle against Assad.

Israel's defense establishment also sees the capture of Quneitra as key to the fighting due to its strategic location on the road leading from south Syria to Damascus. Assad had already lost control over Syria's border crossings, mainly those with Iraq and Turkey. In the Golan Heights, the buffer zone between Syria and Israel - excluding Quneitra - has already been taken under the control of rebel groups.

Two shells fired during the clashes landed inside the Israeli-held territory early Thursday, causing no casualties or damage. An IDF spokeswoman said the area leading to Quneitra had been closed off, but gave no other details on the fighting.

Earlier on Thursday, a Filipino peacekeeper in the Golan Heights was wounded during fighting between Syrian government and rebel forces, a Philippines military spokesman said.

The soldier suffered a leg injury from an artillery or mortar shell that landed at Camp Ziouni, a logistics base for the UN Disengagement Observer Force, said Lt. Col. Ramon Zagala.

The soldier, one of the more than 300 Filipino peacekeepers, was in stable condition, Zagala said.

It was unclear whether the shell came from the government or rebel side.

The incident highlights the vulnerability of peacekeepers in the Syrian conflict.

In March, 21 Filipino peacekeepers were taken captive by a rebel group which released them unharmed after four days. The same group, the Yarmouk Martyrs Brigade, seized four more Filipino soldiers last month and released them five days later.

Philippine Foreign Secretary Albert del Rosario recommended the pullout of all Filipino peacekeepers from the Golan Heights after the latest abduction. President Benigno Aquino III has not yet approved the recommendation.

Meanwhile, Josephine Guerrero, a UN Disengagement Observer Force representative said "I can confirm heavy fighting in the area and that two peacekeepers sustained minor injuries." She did not specify their nationalities.

Open gallery view Golan Heights fire caused by clashes between Syrian army and rebels, June 6, 2013. Credit: AFP