Tel Aviv air raid sirens wailed yesterday for the first time since the first Gulf War as Israel's second most strategically important city was targeted by Palestinian militants armed with long-range rockets.

Both sides continued to hurl munitions at each other without pause as Operation Pillar of Defense (AKA Operation Pillar of Cloud) entered its third day.

The IDF reported striking over 500 targets across the Gaza Strip since the start of the campaign, including the home of Hamas leader Ismail Haniyeh, while over 550 rockets were lobbed at Israel in retaliation. Israel's Iron Dome defense system, however, has managed to intercept a sizable chunk of those aimed at populated areas, allowing only two dozen or so hit the ground (see video, left).

Still, damage is being done on both sides.

In Israel, several houses and a school were destroyed by direct rocket hits. On the Palestinian side, officials are reporting seven additional deaths since yesterday, raising the total to 20. An additional 235 are said to have been wounded.

The arrival of Egyptian PM Hesham Kandil to the region this morning was supposed to trigger a temporary cease-fire, but hopes were quickly dashed as militants continued to fire rockets from Gaza prompting the Israeli Air Force to return violence.

As the conflict maintains a steady escalation, the threat of a ground component grows.

The IDF announced yesterday evening that it was calling up over 30,000 reservists — the largest mobilization of reservists in four years — to prepare for the possibility of a ground operation.

Israel's Deputy Foreign Minister Danny Ayalon told CNN this morning that if rockets continue to fall over "the next 24 to 36 hours," a Gaza incursion may be inevitable.

Meanwhile, on the heart-and-minds front, the IDF and Hamas continued to rely on social networks to spread their respective propaganda. Giving humanity a glimpse of warfare in the 21st century, surreal self-shots of IDF soldiers on Instagram and the gamification of the IDF website were as much a part of the narrative as the conflict itself.

UPDATE: Hamas militants fire missiles at Jerusalem for the first time. No damage or injuries were reported.

[photo via AP]