Israel bombarded Gaza with more air strikes on Monday ahead of an anticipated ground operation into the besieged Palestinian enclave as the United Nations warned that civilians were running out of places to seek shelter.

In signs that the conflict was spreading, Israeli aircraft also struck southern Lebanon overnight and Israeli troops clashed with Palestinians in occupied West Bank, residents said. China's Middle East special envoy, Zhai Jun, who is visiting the Middle East, described the situation as "very serious" with the risk of a large-scale ground conflict rising and the spread of armed conflicts along neighboring borders.

More aid crossed the border into Gaza on Sunday but the UN humanitarian agency said it was just a fraction of the amount needed to help a desperate population which has for two weeks been cut off from outside supplies of food, water, medicine and fuel. Health authorities in Gaza said at least 4,600 people have died in Israel's two-week bombardment following the Hamas assault on October 7 in which 1,400 Israelis were killed and 212 taken as hostages.

READ MORE:

Israel fires on Egypt-Gaza border, France allows pro-Palestine demos

Gaza healthcare system on 'verge of complete collapse' – UK surgeon

Israel delayed by logistics, politics and the 'Gaza Metro' – expert

The Israeli military said on Monday morning that in the past 24 hours it had struck more than 320 targets in Gaza, including a tunnel housing Hamas fighters, and dozens of command and lookout posts. It said in a statement that it destroyed sites "liable to endanger the troops who are preparing on the Gaza periphery for a ground maneuver" as well as dozens of mortar and anti-tank missile launcher positions.

Palestinian media reported that the Israeli attacks concentrated on the Gaza Strip's center and north. A strike on a house near the Jabalia refugee camp in northern Gaza killed several Palestinians and wounded others, according to media reports.

Ground assault 

Israeli troops and tanks are now massed on the Israeli-Gaza border but how soon they might launch a ground incursion, which Israel says is aimed at "destroying" Hamas, was not clear. 

Asked in an interview with Army Radio if Washington was pressuring Israel to hold off on that, Israel's deputy ambassador to the U.S. Eliav Benjamin said: "We and the U.S. administration have been in dialogue from day one. They understand that we are conducting the war in accordance with our interests. In the end of the day, we will do what we need to do when we need to do it."

Wide areas of Gaza have been flattened by the bombing campaign. The UN humanitarian office (OCHA) said about 1.4 million of Gaza's 2.3 million population were now internally displaced, with many seeking refuge in overcrowded UN emergency shelters.

Israel has ordered Gaza residents to evacuate the north to avoid being caught up in the fighting. But OCHA said anecdotal evidence indicated that hundreds and possibly thousands of people who had fled were now returning to the north due to bombardments in the south and lack of shelter.

Israel's military said on Monday that ground forces had mounted limited raids into the Gaza Strip overnight to fight Palestinian gunmen. Hamas said the infiltration was carried out by what it described as an armored force in southern Gaza, adding that it destroyed two bulldozers and a tank and "forced the force to withdraw."

Spreading violence

Fears that the Israel-Hamas conflict could mushroom into a wider Middle East war rose over the weekend with Washington claiming there was a significant risk to U.S. interests in the region and announcing a new deployment of advanced air defenses.

Along Israel's northern border with Lebanon, Israeli forces fired on fighters of the Iran-backed Hezbollah group which support the Palestinian cause, the deadliest escalation of frontier violence since an Israel-Hezbollah war in 2006.

Early on Monday, Israel said its aircraft had bombed two Hezbollah cells in Lebanon that were allegedly planning to launch anti-tank missiles and rockets toward Israel. Israel's military also said it struck other Hezbollah targets, including a compound and an observation post. 

Hezbollah said on Monday one of its fighters was killed, without providing details. Israel's military said seven soldiers have been killed on the Lebanese border since the latest conflict began.

In the West Bank, two Palestinians were killed at the Jalazone refugee camp near Ramallah, the Palestinian health ministry said on Monday. Residents said that Israeli forces raided the camp and made many arrests as they clashed with gunmen and some youths who threw stones. The Israeli army has not issued a statement about the incident.

International response

China's Middle East special envoy Zhai Jun, who is visiting the region, said Beijing was "deeply concerned about the sharp escalation of the conflict," adding that the fundamental way out of the Palestinian-Israeli conflict was to implement the two-state solution and establish an independent Palestinian state. 

Zhai, making the remarks at the Cairo Summit for Peace, added that China condemns all acts that harm civilians, opposes any violation of international law, and was urging the immediate cessation of military operations that could fuel the situation.

The continuous escalation of the Palestinian-Israeli conflict once again proves that the Palestinian issue should not be ignored and forgotten, Zhai said, adding that a more authoritative, influential, and wide-ranging international peace conference was needed on the crisis. Having already spoken with the foreign ministry heads of the Palestinians, Israel, Egypt, as well as with the special representatives of the UN and EU, Zhai is now set to visit the United Arab Emirates, Saudi Arabia, Jordan and other countries in the region to strengthen coordination aimed at ending the crisis.

Meanwhile, leaders of the U.S., Canada, France, Germany, Italy and Britain on Sunday underscored their support for Israel's right to defend itself, but also called on their regional ally to adhere to international humanitarian law and protect civilians. U.S. President Joe Biden convened the meeting of the wealthy Western nations' leaders after speaking with Israeli Prime Minister Benjamin Netanyahu amid growing fears of a wider conflagration. The Western leaders later published a joint statement in which they called for the release of Israeli hostages, while pledging their commitment to getting aid to Gaza and "prevent[ing] the conflict from spreading."

Palestinian Prime Minister Mohammad Shtayyeh has called for international unity to stop Israel's attacks in Gaza and allow aid after a second convoy of 14 aid trucks entered the Rafah crossing from Egypt into Gaza on Sunday night. The White House said U.S. President Joe Biden and Israeli Prime Minister Benjamin Netanyahu had affirmed in their call there would now be a continued flow of aid into Gaza.

That's despite an Israeli tank "accidentally" firing on an Egyptian position near the border with the Gaza Strip during Sunday's delivery, with several Egyptian border guards sustaining minor injuries. Israel's defense force later expressed "sorrow regarding the incident, which is being investigated," it said in a statement, giving no further details.

The UN humanitarian office said the volume of aid entering Gaza so far was just 4 percent of the daily average before the hostilities and a fraction of what was needed. The aid shipments did not include fuel.

Subscribe to Storyboard: A weekly newsletter bringing you the best of CGTN every