Human Rights Watch said Israel’s ongoing aerial bombardment in Lebanon has put civilians “across the country at grave risk,” and called for a United Nations investigation into strikes in Lebanon and rocket fire by Hezbollah militants into northern Israel.

The global rights group documented over a thousand Israeli strikes across Lebanon since the Israeli military announced a new phase in its conflict with Hezbollah, which has launched over 200 rockets into northern Israeli towns.

U.S. Secretary of State Antony Blinken is urging both Israel and Hezbollah to step back from their intensifying conflict, saying that an all-out war would be disastrous for the region and its people.

In New York for the annual U.N. General Assembly, Blinken said Wednesday the U.S. was working on a plan to de-escalate tensions and allow tens of thousands of Israelis and Lebanese to return to homes they have had to evacuate in border areas.

The Israeli army chief said Wednesday that the military is preparing for a possible ground operation in Lebanon as Hezbollah hurled dozens of projectiles into Israel, including a missile aimed at Tel Aviv that was the militant group's deepest strike yet.

Addressing troops on the northern border, Chief of Staff Lt. Gen. Herzi Halevi said the latest Israeli airstrikes were designed to "prepare the ground for your possible entry and to continue degrading Hezbollah."

The United Nations said Wednesday that some 90,000 people had been displaced in Lebanon this week, as Israel pounds what it says are Hezbollah targets across the country and the Lebanese group strikes back.

Since Monday, the U.N.'s International Organization for Migration has recorded "90,530 newly displaced persons", a statement said.

Israel’s Northern Command chief General Ori Gordin inspected an army exercise on Lebanon’s border on Tuesday and said troops there “must prepare very strongly to move to a ground maneuver.”

As Israeli bombs flattened buildings and sent smoke billowing skywards over Lebanon this week, Gazans looked on with both empathy and fear over how the widening war might affect them.

Israel carried out a third day of air strikes against Lebanon on Wednesday, saying it was targeting weapons caches and infrastructure belonging to Hezbollah.

The Israeli military said on Wednesday it was calling up two reserve brigades to the north, where its forces are involved in cross-border clashes with the Lebanese group Hezbollah.

"The IDF (military) is calling up two reserve brigades for operational missions in the northern arena," the military said in a statement, adding that this would "enable the continuation of combat against the Hezbollah terrorist organization".

Parliament Speaker Nabih Berri revealed to Asharq al-Awsat newspaper on Wednesday that he is carrying out “serious efforts” with international parties, including the U.S., to halt the ongoing Israeli escalation against Lebanon.

After almost a year of trading fire, Israel and the Lebanese Hezbollah are now engaged in ferocious confrontations that threaten to turn into a full-blown war.

Israel faces a much more formidable foe in Hezbollah than it faced in Hamas in the Gaza Strip. Many consider the Iran-backed group the strongest paramilitary force in the region — but the group also has political and social wings with considerable power in Lebanon.

The White House said Wednesday that a missile launched by Hezbollah in Lebanon at Tel Aviv in Israel was "deeply concerning," but that a diplomatic offramp remains to avoid "all-out war."

"It's certainly deeply concerning, obviously to the Israelis, of course, but also to us," White House National Security Council spokesman John Kirby told CNN. "There is still time and space for a diplomatic solution here to de-escalate the tensions and to prevent an all-out war."