A Syrian flag
A Syrian flag flutters on a pole near the Quneitra crossing in Syria close to the border fence with the Israeli-occupied Golan Heights Reuters

Mortar shells from Syrian fighting between rebels and Assad troops have landed in the Israeli Golan Heights prompting a response from the Israel Defense Forces (IDF).

The mortar was likely an accidental spillover from the Syrian civil war and no injuries or damage were reported in the incident, according to the Jerusalem Post. Sirens went off in a number of communities in the area. In response, the IDF, which holds the Syrian army responsible for cross-border fire, fired a Tamuz surface to surface missile at the origin of the attack.

The al-Qaida-linked al-Nusra front, a prominent Islamist rebel group, seized the strategic Quneitra border crossing with help of Western backed Free Syrian Army, trapping UN peacekeepers units deployed in the buffer zone between Israel and Syria. The siege of 70 Filipino UN personnel lasted two days while 45 Fijian UN soldiers are still in the hands of al-Nusra.

Israel, which has stayed on the sidelines of the Syrian civil war, is now worried about al-Qaida fighters moving just 50 metres away from IDF military outposts and farmers' fields. The Golan plateau was seized by Israeli forces in the 1967 war. It later annexed the area and since the 1973 war UN monitoring troops have been deployed there to enforce a truce.

The Quneitra crossing is considered an important military success for the Nusra front as it gives them an access to Israeli-held territory between the two countries. The crossing also allows Syrian rebels to open a new front on Damascus, connecting them with to southern outposts of Qalamoun. As security analyst Daniel Nisman stated on Twitter: