(CNN) -- Deteriorating security conditions near the Golan Heights headquarters for U.N. peacekeepers in the region has prompted Austria to say it will pull out its 370 troops, more than a third of the force assigned to help keep Israel and Syria at bay.
The announcement came amid fierce fighting over the Quneitra crossing, Syria's only access point to the Golan Heights. Rebel forces first captured but then lost control of the crossing in heavy fighting.
Syrian tanks crossed into a demilitarized zone near the crossing, Israel complained to the United Nations, and two U.N. peacekeepers were wounded when an errant mortar round fell on their border camp.
A CNN team also could see Israeli tanks taking up positions along the border on the Israeli-occupied side of the Golan Heights.
The developments come amid longstanding concerns that the bloody 2-year-old Syrian conflict could widen into a broader regional conflict.
Israel Foreign Affairs Ministry said it regretted Austria's decision to pull its troops out and said Israeli officials "hope that it will not be conducive to further escalation in the region."
U.N. spokeswoman Josephine Guerrero said Filipino and Indian peacekeepers will remain in the region to enforce the peace deal between Israel and Syria reached in 1974, nearly seven years after Israel first captured Quneitra in the Six-Day War. Syria retook it in 1973.
Guerrero said the U.N. will also look to other countries to bring troops to bolster the force, which has suffered from several security incidents in recent months.
Last month, U.N. officials said Syrian rebels detained four Filipino peacekeepers, and in December, two Austrian peacekeepers were wounded after being caught in crossfire between Syrian government troops and rebels.
The fighting in Quneitra could be seen on Thursday from the Israeli-occupied side of the Golan Heights. Rebels fired on the Syrian forces, who responded with tank fire. Mortars and small arms fire set bushes and shrubs ablaze.
Israeli Defense Force spokesman Peter Lerner said the military was taking precautions to prevent the conflict from spilling over into Israel.
Israeli authorities have told farmers in the Golan Heights not to approach the border fence in the Quneitra area due to the fighting on the Syrian side, Lerner said.
Quneitra is important to the Syrian regime because it represents former President Hafez al-Assad's attempt to liberate Israeli-occupied territory.
In another sign that Syria's civil war is spilling across borders, at least 10 missiles from Syria landed overnight on the eastern Lebanese city of Baalbek, the Lebanese army said Thursday.
The rockets wounded one person and damaged property, the army said.
Baalbek's population has grown 50% in recent months because of the influx of Syrian refugees fleeing their country's violence.
But it appears the violence is following them.
CNN's Tom Watkins, Kareem Khadder, Ben Wedeman, Arwa Damon, Michael Schwartz and Nada Husseini contributed to this report.