Austria began pulling out its UN peacekeepers from the Golan Heights days after Vienna decided to quit the mission over deteriorating security concerns.
An AFP photographer said on Wednesday 20 soldiers in jeeps accompanied by tanks entered the Israeli side of the Quineitra Crossing – the only direct passage between Israel and Syria.
Another 50 soldiers out of the 378-strong force were to pull out throughout the day, according to sources on the ground. The Austrian defence ministry said the full withdrawal would be completed by June 24.
Vienna’s decision on Tuesday came after Syrian opposition rebels briefly seized the Quneitra crossing late last week, in an incident in which two UN troops were injured.
The crossing lies in the demilitarised zone on the Israel-Syria armistice line and is monitored by about 1,000 UN peacekeepers, including the Austrians.
On Tuesday, a senior Israeli official said dozens of Austrian soldiers had already left the mission’s headquarters. Israeli public radio said they were administrative staff.
"But the majority of soldiers will remain in place until the UN has found a country that can send troops to replace the Austrian ones," said an Israeli official, who asked not to be named.
The UN is trying to persuade Austria to slow down its withdrawal.
The country has played an important role as part of the UN force monitoring a ceasefire between Syria and Israel since 1974.
Japan and Croatia have also withdrawn their forces in recent months, as battles between Syrian government and opposition forces spill into the ceasefire zone.
Russian President Vladimir Putin said last week that troops from his country could replace the Austrians, but under the terms of the 1974 accord that created the force, members of the UN Security Council are not allowed to take part.