Syria border (file)
Syria border (file)Reuters

As fighting intensified between Syrian army troops and Islamist rebels, the IDF increased its presence on the Golan Heights Monday afternoon. Security officials fear that the fighting could “spill over” the Israeli border.

A senior Israeli security official said that the IDF had recently changed its conception of defense on the Golan. A group of highly trained and experienced soldiers who know the terrain well are now on duty at all times, constituting a forward force ready to deal with trouble as it develops.

The fighting heated up on the Syrian side of the border on Monday, with the sounds of battle distinctly heard in Israel. The heaviest fighting is in the area of the city of Quneitra, just over the border.

From what they can tell, IDF officials say that the casualty rate was very high in the Syrian Golan, with victims on both sides of the battle. According to reports, the Syrian Army's regional commander in the Golan was among those killed in battle.

The IDF is continuing to examine the remains of a UAV shot down over the Golan Sunday. The Israeli Air Force downed the unmanned drone over the Golan Heights as it attempted to enter Israeli airspace from Syria. Forces fired a surface-to-air Patriot missile at the drone, which came from the area of Quneitra.

According to security sources, the drone was made in Iran. Israeli officials are examining what the model for the drone was – especially if it was based on American models, specifically the US drone that was reportedly downed over Iran last year.

The fighting has been spilling over, as a mortar shell fired from Syria struck an open area on the Israeli side of the Golan Heights Monday morning, with the battle continuing to rage between pro-regime forces and Syrian rebels. No damage or injuries were reported.

Several mortar shells have fallen inside Israeli territory since the launch of a rebel offensive centered around the Syria border city of Quneitra last Wednesday.

An alliance of rebel forces, including both the western-backed Harakat Hazm faction and Al Qaeda's Syrian branch the Al-Nusra Front, drove out Assad regime forces last week, but have been facing a concerted counterattack by Syrian army ground and air forces since.