UPDATE, 1:30p ET: Israel's defense minister called for the mobilization of approximately 75K Israeli troops in 'preparation for likely ground invasion,' Fox News report. The U.N. has called on both sides to back down.

Air raid sirens sounded throughout Jerusalem this morning, signaling a possible rocket attack as other fire from Gaza targeted Tel Aviv.

Fox News correspondent Leland Vittert reported live from the Gaza border in Israel, where he said a major escalation is under way in the conflict.

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  • "There have never been rockets fired on Jerusalem, and [it's the] first time on Tel Aviv in almost 20 years, both of which are going to illicit a very strong response from Israel," he said. He added that on the ground in the region, there's a very 'eerie feeling that an all-out ground offensive by Israel is imminent.'

    Learn more in his report below: