Israel "seized" territory in Syrian-controlled areas of the Golan Heights over the weekend with Prime Minister Benjamin Netanyahu saying he ordered his army to "take control" of the buffer zone established by a 1974 ceasefire deal with Syria.

"We will not allow any hostile force to establish itself on our border," Netanyahu said, following the lightning advance by Syrian opposition forces which ended Bashar al-Assad's rule over the weekend.

Netanyahu said the decades-old UN-monitored Disengagement Agreement had collapsed and that Syrian soldiers had abandoned their positions, necessitating the Israeli takeover.

Israel captured part of the Golan Heights from Syria in the 1967 Arab-Israeli War before annexing the territory in 1981. The annexation is not recognized by the UN. In 1974 a UN force was sent into the buffer zone to monitor a ceasefire.

It now means an extra front for Israeli's military. After Sunday's latest offensive, IDF Chief of Staff Herzi Halevi said: "Ground troops are engaged in combat on four fronts: Against terrorism in Judea and Samaria, in Gaza, in Lebanon, and last night we deployed troops into Syrian territory."

Israel's Foreign Minister Gideon Saar said on Monday that his country's military takeover of the buffer zone along its border with Syria was a "limited and temporary step. Netanyahu added that Israel was working on a policy of "good neighborliness."

Jordan and Egypt both denounced the deployment of the Israeli army in the Golan buffer zone in southwestern Syria.

An Egyptian Foreign Ministry statement described the Israeli grab move as "an occupation of Syrian territories and a flagrant violation to the 1974 Disengagement Agreement."

It also called the Israeli practices a breach of international law and a violation of Syria's territorial integrity.

'Unacceptable escalation'

Jordan's Foreign Minister Ayman Safadi said: "We categorically reject this aggression and affirm that when we speak of the unity of Syria, its territorial integrity and its cohesion, this also includes its borders with Israel."

He denounced the "aggression" which represents "a violation of international law, an unacceptable escalation and an attack on the sovereignty of an Arab state."

Israel also announced they would step up airstrikes on Syrian stores of advanced weaponry and keep a 'limited' troop presence on the ground.

While Assad's fall wiped out a bastion from which Israel's rival power Iran had exercised influence in the region, the advance of Syria's rebel forces with roots in the Islamist ideology of Al Qaeda poses risks.

And following the Hamas attack just over a year ago, Israel is looking to head off any future threat from its neighbors or internal factions.

Israel's Foreign Minister Saar said: "That's why we attack strategic weapons systems like, for example, remaining chemical weapons or long-range missiles and rockets in order that they will not fall into the hands of extremists."