Follow NBC News' latest updates on the Israel-Hamas war: southern Gaza bombarded after cease-fire talks collapse, U.S. urges IDF to protect civilians.

Israel is bombarding the southern Gaza Strip with airstrikes and artillery shells after a weeklong truce with the terror group Hamas collapsed Friday. The Israel Defense Forces says it struck more than 200 terrorist targets and fighting has resumed with Hezbollah terrorists on the country's northern border with Lebanon.

Beleaguered Gazans, having fled the territory’s north, emerged from a night of bombardment wondering where to go next for safety.

Analysis: With nearly the entire Palestinian population of Gaza concentrated in the south, the next phase of Israel's war will create an unprecedented humanitarian disaster.

The Israeli army offensive has moved towards the city of Khan Younis in southern Gaza Elsewhere, Israel struck Hezbollah militia positions in southern Lebanon. Israel strikes Hezbollah positions in Lebanon Israel's military has again struck Helzbollah militia positions in southern Lebanon in response to what it says was shelling from across the border.

On the ground in Gaza, Israeli troops are moving south and prompting more civilian evacuations. And as tension grows in the Middle East, the U.S. military says it fended off attacks on commercial vessels in the Red Sea.