Lebanese troops opened fire on Syrian warplanes violating Lebanese airspace on Monday. According to Lebanon's National News Agency, the incident occurred as the Syrians raided Khirbet Daoud, which lies between Homs and Damascus on the Lebanese side of the border.

The Lebanese response is thought to be the first of its kind in the Syrian war. Lebanon has previously avoided responding to Syrian attacks on rebel shelters in its territory so as not to be dragged into the bloody conflict.

The recent military action comes on the heels of an announcement that Saudi Arabia will contribute $3 billion to fund the Lebanese army. The announcement is being seen as part of the Gulf state's rigorous efforts to counter Iranian influence in the region, as Riyadh pursues a more aggressive foreign policy following tensions with the US over how to handle the Syrian conflict.

Since late October the Syrian regime has been undertaking a large-scale offensive in the Qalamoun mountain region to cut off rebel supply routes from Lebanon. The fighting has displaced roughly 20,000 Syrians, who have settled in the Khirbet Daoud area. Syrian army forces are being aided by foreign Shia militias - among them Iranian-backed Hezbollah, which wields considerable influence within Lebanon.

The Qalamoun region is largely Sunni and supportive of the predominantly Sunni rebel forces in their fight against Syrian President Bashar Assad. Assad's Alawite sect is an offshoot of Shia Islam.

The extent towards which the conflict in Syria has contributed towards exacerbating Muslim sectarian tensions in the Middle East were highlighted recently as Iraqi Prime Minister Nuri Al-Maliki called for Shia Muslim prayers to be directed to the Shi'ite holy city Karbala, instead of Mecca.

January 22 has been picked as the date for Geneva II peace talks to try and find a diplomatic solution to the Syrian war now in its third year, which has left over 100,000 dead and created over 2 million refugees.

On Sunday, rockets were fired at Israel from Lebanon, eliciting an immediate response by the IDF. Prime Minister Binyamin Netanyahu blamed the Lebanese government, holding it responsible for attacks emanating from its territory.