Israel has escalated its military campaign against the Lebanon-based Hezbollah group, including launching a ground invasion, after a year of exchanges of fire during its war with Hamas in the Gaza Strip.

The fighting in Lebanon has driven 1.2 million people from their homes, most of them fleeing to Beirut and elsewhere in the north over the past three weeks since the escalation.

Ted Chaiban, UNICEF’s deputy executive director for humanitarian actions, has visited schools that have been turned into shelters to host displaced families.

“What struck me is that this war is three weeks old and so many children have been affected,” Chaiban told The Associated Press in Beirut.

“As we sit here today, 1.2 million children are deprived of education. Their public schools have either been rendered inaccessible, have been damaged by the war or are being used as shelters. The last thing this country needs, in addition to everything else it has gone through, is the risk of a lost generation.”

While some Lebanese private schools are still operating, the public school system has been badly affected by the war, along with the country’s most vulnerable people such as Palestinian and Syrian refugees.

″What I’m worried about is that we have hundreds of thousands of Lebanese, Syrian, Palestinian children that are at risk of losing their learning,” Chaiban added.

More than 2,300 people in Lebanon have been killed in Israeli strikes, nearly 75% of them over the last month, according to the Health Ministry. In the last three weeks, more than 100 children were killed and over 800 were wounded, Chaiban noted.

He stated displaced children are crammed into overcrowded shelters where three or four families can live in a classroom separated by a plastic sheet, and where 1,000 people can share 12 toilets. Not all of them work.

Many displaced families found have set up tents along roads or on public beaches.

Most displaced children have experienced so much violence, including the sounds of shelling or gunshots, that they cower at any loud noise, Chaiban said.

Then there is “evacuation orders upon evacuation orders. We’re at the beginning, and already there’s been a profound impact”, he added.

The escalation has also put over 100 primary health care facilities out of service, while 12 hospitals are either no longer working or partially functional.

Water infrastructure has also come under attack. In the last three weeks, 26 water stations providing water to almost 350,000 people have been damaged, Chaiban continued. UNICEF is working with local authorities to repair them.

He called for civilian infrastructure to be protected. And he appealed for a cease-fire in Lebanon and in Gaza, saying there needs to be political will and a realization that the conflict cannot be resolved through military means.

“What we must do is make sure that this stops, that this madness stops, that there’s a cease-fire before we get to the kind of destruction and pain and suffering and death that we’ve seen in Gaza.”

With so many needs, he added, the emergency response appeal for $108 million in Lebanon has only been 8% funded three weeks into the escalation.

According to the official Lebanese National News Agency, Lebanon’s mission to the UN in New York filed the complaint under the instructions of Foreign Minister Abdullah Bou Habib to both the UN Security Council and Secretary-General Antonio Guterres.

The Lebanese diplomatic mission said the Israeli attack on UNIFIL is “a dangerous precedent and a blatant violation of the international law”, that comes to jeopardize UNIFIL’s mission.

It urged for “a decisive and firm stance” against those attacks that “mount to war crimes”, and hold Israel accountable for its violations to prevent their repetition.

Israeli tanks on Sunday forced entry into one of UNIFIL’s positions, latest in a series of violations and attacks by the Israeli military, which injured several peacekeeping troops.

Last week, four UNIFIL peacekeepers were injured by Israeli army’s shelling on their posts in southern Lebanon.

UNIFIL was established as interim force in 1978 to help restore peace in the region and as a confirmation of Israeli withdrawal from Lebanon.

Israel has mounted massive airstrikes across Lebanon against what it claims are Hezbollah targets since Sept. 23, killing at least 1,550 people, injuring over 4,555 others, and displacing more than 1.34 million people.

The aerial campaign is an escalation from a year of cross-border warfare between Israel and Hezbollah since the start of its offensive on the Gaza Strip, in which Israel has killed nearly 42,300 people, most of them women and children, since a Hamas attack last year.

Despite international warnings that the Mideast was on the brink of a regional war amid Israel’s relentless attacks on Gaza and Lebanon, it expanded the conflict on Oct. 1 by launching a ground incursion into southern Lebanon.