Israel is deliberately targeting Palestinian children in what has become a key factor in an ongoing "genocide" in Gaza, United Nations investigators charged on Tuesday.

The U.N. Independent International Commission of Inquiry said it had found evidence that "Palestinian children have been deliberately targeted and killed by Israeli security forces", which it called a key factor in establishing "the genocidal intent of the Israeli authorities and security forces to destroy the larger Palestinian group in Gaza".

Italy's health ministry declared a red heatwave alert in 15 cities including Milan and Rome on Tuesday and said the number would go up to 16 on Wednesday.

During a red alert -- the highest level -- the ministry advises people to eat light, stay indoors in the hottest parts of the day and sprinkle themselves with cool water.

Technical talks between Iran and the United States in Switzerland have concluded, with negotiating groups to be set up on nuclear issues and sanctions, Iran's state media reported Tuesday.

The negotiators "decided that four working groups would be established: Sanctions Termination, Nuclear Affairs, Reconstruction and Economic Development, and Monitoring and Implementation," said IRNA state news agency, quoting Deputy Foreign Minister Kazem Gharibabadi.

After a first round of U.S.-Iran talks in Switzerland on ending the Middle East war, mediators Pakistan and Qatar said on Monday that Tehran and Washington had agreed to set up a "de-confliction cell" with Lebanon "to ensure the adherence of the termination of military operations" there.

Under U.S. pressure, Lebanese officials began direct talks with Israel in April in Washington, and a fifth round of negotiations is scheduled to begin on Tuesday.

Direct damage to buildings in south Lebanon in the latest war between Israel and Hezbollah is estimated at around $1.38 billion, a U.N. agency and a Lebanese research center said Monday.

President Joseph Aoun stressed Monday that Lebanon would negotiate for itself regarding the conflict with Israel.

U.S. Vice President JD Vance said Monday that a first round of U.S.-Iran talks in Switzerland had laid a good foundation for reaching a final deal on ending the Middle East war.

"We laid a very good foundation for a successful final deal," Vance told reporters at the Burgenstock resort in central Switzerland, following negotiations that started on Sunday and went on into the night.

President Joseph Aoun spoke with senior U.S. and Qatari officials on Monday about consolidating a ceasefire in Lebanon and forming a "de-confliction cell", his office said, after U.S.-Iran negotiations in Switzerland.

Fighting between Israel and Hezbollah has repeatedly threatened to derail regional peace efforts.

Syrian President Ahmed al-Sharaa has denied that his country sought to intervene militarily in Lebanon where Israel and Hezbollah are at war, after U.S. President Donald Trump repeatedly suggested Damascus could get involved.

"We are looking for economic channels between Lebanon and Syria, not military ones," Sharaa said in an interview broadcast on television channel Al Mashhad.

There was cautious calm Monday in Lebanon, with no Israeli strikes reported overnight after a day of quiet Sunday.

Hezbollah likewise has not announced any attacks on Israeli forces since Saturday.