U.S. Vice President Kamala Harris, the presumptive Democratic election nominee, said Tuesday that Israel had a "right to defend itself" following a strike in Hezbollah's stronghold in Beirut's southern suburbs.

Harris -- who last week struck a tough tone with Israeli Prime Minister Benjamin Netanyahu over Israel's war on Gaza -- also called for a diplomatic solution to reduce the risk of all-out conflict on the Lebanon-Israel border.

U.N. Special Coordinator Jeanine Hennis-Plasschaert on Tuesday said she is "deeply concerned" after Israel's strike in "the densely populated southern suburb of Beirut which resulted in multiple civilian casualties."

"The Special Coordinator underscores once again that there is no such thing as a military solution and calls on both Israel and Lebanon to avail of all diplomatic avenues to pursue a return to the cessation of hostilities and to recommit to the implementation of resolution 1701 (2006)," a statement issued by her office said.

Iran condemned Tuesday what it called a "vicious" Israeli strike in Beirut's southern suburbs which Israel said targeted a Hezbollah commander behind last week's rocket strike on the Israeli-annexed Golan Heights.

Caretaker Prime Minister Najib Mikati on Tuesday condemned an Israeli strike on Hezbollah's stronghold in Beirut's southern suburbs that killed at least one person and wounded 68 others, days after Israel vowed to retaliate over deadly rocket fire on the occupied Golan Heights that it said came from Lebanon.

Mikati "condemned the blatant Israeli aggression on the southern suburbs of Beirut," the premier's office said in a statement, describing it as a "criminal act" in a "series of aggressive operations killing civilians in clear and explicit violation of international law."

Russia accused Israel on Tuesday of violating international law after it struck a Hezbollah stronghold in the suburbs of the Lebanese capital Beirut.

"This is a gross violation of international law," Russia's foreign ministry told state news agencies.

Israel carried out a rare strike Tuesday on Beirut's southern suburbs that killed at least four civilians -- two children and two women -- and wounded around 74 others, raising the stakes in the escalating tensions with Hezbollah.

The Israeli military said the strike targeted and killed Hezbollah's "most senior" military commander, Fouad Shukur, accusing him of being behind the deaths of 12 children and teens in a weekend rocket strike on a Druze village in the Israeli-controlled Golan Heights, as well as the deaths of numerous Israeli civilians hit in other strikes.

By Mireille Rebeiz, Dickinson College

A missile strike that killed 12 children playing soccer in the Israeli-occupied Golan Heights on July 27, 2024, has prompted international concern that the Middle East conflict could expand into the disputed territory.

Fears of an escalation in the simmering conflict between Hezbollah and Israel have prompted some airlines to cancel flights to Lebanon, but business appeared to be proceeding as usual Tuesday at the Beirut airport, where many travelers greeted the warnings with a shrug.

Hadi Sharqawi, 24, a Lebanese student in Italy, arrived Tuesday after two days of flight cancellations, to spend a month and a half with his family as he normally does in the summer. He is from the town of Kharayeb, which is in southern Lebanon although relatively far from the border where clashes have been ongoing for 10 months.

Hezbollah Secretary-General Sayyed Hassan Nasrallah has expressed gratitude to Druze leader Walid Jumblat “in appreciaion of his stances on the war on Gaza and south Lebanon for the past 10 months, specifically over his latest stance on the rocket attack on Majdal Shams,” the pro-Hezbollah al-Akhbar daily reported on Tuesday.

Jumblat “confronted the attempts to stir strife and exploit the incident,” al-Akhbar said.

Hezbollah on Tuesday said that it is taking the latest Israeli threats seriously and that it is “fully prepared” for any Israeli strike linked to Saturday’s deadly rocket fire on the Golan’s Majdal Shams.

“The enemy’s talk of a harsh and limited strike does not concern us at all, because it will be an aggression regardless of its magnitude,” a senior Hezbollah leader told Al-Jazeera television.