Israeli Warplanes Strike Inside Syria for Fifth Time This Year For the fifth time this year Israeli warplanes launched airstrikes inside Syria.

Oct. 31, 2013 -- Israeli warplanes conducted an airstrike early today on a Syrian military facility near the northern Syrian port city of Latakia along the Mediterranean coast, a U.S. official confirms to ABC News.

The attack is believed to be the fifth airstrike conducted by Israel inside Syria this year. Like the earlier airstrikes, the official said the latest attack presumably targeted advanced Russian missile weapons systems headed to the extremist group Hezbollah based in Lebanon.

An Israeli source also confirmed the attack to ABC News which like the four previous attacks this year has not been acknowledged by the Israeli government.

The air strike was first reported in Israeli newspapers which cited explosions at a missile storage facility near Latakia. The accounts differed as to what types of air defense missile systems may have been targeted by Israeli warplanes.

U.S. official say that the Israeli warplanes conducting the airstrikes usually launch missiles at targets inside Syria from inside Lebanese airspace so they are not exposed to Syria's advanced air defense systems.

The official Lebanese news agency reported that Israeli planes were spotted flying for several hours over various parts of Lebanon. A Lebanese Army press release said "the enemy planes circled above the various Lebanese regions" before leaving Lebanese airspace.

The most recent Israeli airstrike inside Syria took place on July 5 and also occurred near Latakia, targeting a warehouse that was believed to house advanced Yakhont long-range anti-ship missiles.

The three earlier Israeli air strikes inside Syria all targeted Russian weapons systems that Syria was believed to be funneling to Hezbollah in Lebanon. Syria has been a long-time arms provider to the militant Lebanese organization.

The first strike near Damascus in late January targeted a convoy carrying anti-aircraft missiles that may have been on the move to Hezbollah.

In early May, Israel conducted two separate airstrikes, also near Damascus, that a U.S. official told ABC News targeted as many as a dozen medium range Fateh-110 missiles intended for Hezbollah.