As feared and expected, looks like Hezbollah is now attacking Israel from Lebanon:

Lebanese militants fired at least three rockets into Israel early Thursday, threatening to open a new front for the Jewish state as it pushed forward with a bloody offensive in the Gaza Strip that has killed nearly 700 people. Israel responded with mortar shells.

The rockets that exploded in Israel's north raised the specter of renewed hostilities with Hezbollah, just 2 1/2 years after Israel battled the guerrilla group to a 34-day stalemate. Hezbollah started the 2006 war as Israel was battling Palestinian militants in Gaza.

No group claimed responsibility and Lebanon's government, wary of conflict, quickly condemned the rocket fire, which lightly injured two Israelis.

For a second straight day, Israel said it suspended is Gaza military operation for three hours to allow in humanitarian supplies. Shortly before the pause took effect, however, the U.N. said one of its aid trucks came under Israeli fire, killing the driver.

U.N. spokesman Adnan Abu Hasna said the U.N. coordinated the delivery with Israel, and the vehicle was marked with a U.N. flag and insignia when it was shot in northern Gaza. The Israeli army said it was investigating.

The allegation was sure to raise tensions with the United Nations, which has already demanded an investigation into Israel's shelling of a U.N. school in Gaza that killed nearly 40 people. At the time, Israel said it opened fire after militants hiding in the crowd shot mortar shells at Israeli troops.

Before the lull on Thursday, Israel killed at least 11 people in Gaza, including five militants, raising the death toll from its 13-day offensive to 699 people, according to Palestinian medical officials. The offensive is meant to halt years of Palestinian rocket attacks on southern Israel, but with roughly half the dead believed to be civilians, international efforts to broker a cease-fire have been gaining steam.

[...] Israel has repeatedly said it was prepared for a possible attack on the north since it launched its bruising campaign against Hamas militants in Gaza on Dec. 27. Israel has mobilized thousands of reserve troops for such a scenario, and leaders have warned Hezbollah of dire consequences if it enters the fighting.

"We are following what is happening in the north. We are prepared and will respond as necessary," Defense Minister Ehud Barak told reporters.

Lebanese Prime Minister Fuad Saniora condemned both the attacks and Israel's retaliatory fire. The attacks are "the work of parties who stand to lose from the continued stability in Lebanon," Saniora said.