Austria says it is withdrawing its 377 UN peacekeepers from the Golan Heights after Syrian rebels briefly overran a border position before government troops retook it, Belfast Telegraph reported.

Chancellor Werner Fayman and Foreign Minister Michael Spindelegger said that "the development ... has shown that further waiting can no longer be justified".

Rebels attacked the border position near the destroyed city of Kuneitra early on Thursday, June 6. The peacekeepers receive most of their supplies through that position from Israel.

The development is likely to deepen Israel's concerns that the volatile area in the north along the Israel-Syria frontier could fall into the hands of radical Islamic factions fighting with other insurgent groups against President Assad's forces.

The Israeli military said the Israeli side of the crossing had been declared a "closed military zone" and was off limits to journalists because of the fighting nearby.

The incident comes a day after the Syrian military, backed by Lebanese Hezbollah militants, captured the strategic town of Qusair near the border with Lebanon in a significant blow to the opposition fighters trying to topple Assad's regime.