Fears have mounted that Israel's war in Gaza could spread across the region after strikes in Lebanon and Iraq as well as deadly blasts in Iran, but experts say a wider conflict is unlikely for now.

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Caretaker Prime Minister Najib Mikati received a phone call Wednesday evening from French Foreign Minister Catherine Colonna.

Hezbollah targeted Thursday Israeli soldiers and posts in Shtula, Metula, al-Manara and al-Jerdah while Israel struck the outskirts of Houla and Maroun al-Ras and shelled al-Khiam and the Panorama curve -- between Kfarkila and Odeisseh -- with white phosphorus bombs.

Four Hezbollah fighters, including a local Hezbollah leader, were killed overnight in southern Lebanon in Israeli strikes on the border town of Naqoura.

Israel carried out the strike that killed deputy Hamas leader Saleh al-Aruri in Beirut, a U.S. Defense Department official said.

Arouri -- who died Tuesday in an area that is a stronghold of the powerful Lebanese militant group Hezbollah -- is the most high-profile figure to be killed since the Hamas-Israel war in Gaza broke out in October.

Four Hezbollah fighters were killed overnight in southern Lebanon, the Iran-backed movement announced Thursday, in what Lebanese state media said were Israeli strikes on the border town of Naqoura.

The deaths, which according to a source close to the powerful militant group include a local Hezbollah leader, follow a strike on Beirut this week that killed a senior Hamas leader, raising regional tensions as war rages in Gaza.

Fears that Israel's war in Gaza could spiral across the Middle East have mounted after twin explosions ripped through an Iranian crowd, claiming at least 103 lives following a strike in Lebanon that killed Hamas's deputy leader.

More than 200 other people were wounded when the blasts about 15 minutes apart struck mourners commemorating slain Revolutionary Guards general Qasem Soleimani on the fourth anniversary of his killing in a United States drone strike, Iran's state media reported.

Near Israel's tense northern border with Lebanon, residents fear the killing of the deputy leader of Palestinian militant group Hamas in Beirut could spark a war with their neighbor.

During nearly three months of fighting between Israel and Hamas in Gaza, the Israeli army has also been exchanging cross-border fire with Lebanon's Hezbollah, which is allied with Hamas.

Germany has urged its citizens to leave Lebanon quickly, warning that an expansion of the Israel-Hamas war could not be ruled out after a drone strike in Beirut killed a senior Hamas leader.

"All German citizens, who are still in Lebanon, are asked to register on the ELEFAND crisis preparedness list and to leave the country as quickly as possible," wrote the German foreign ministry on X, formerly known as Twitter.

A high-level Lebanese security official has told AFP that Israel fired guided missiles from a warplane to kill Hamas number two Saleh al-Arouri in a Beirut suburb.

Lebanese authorities and Hamas accused Israel of killing Arouri in Beirut's southern suburbs on Tuesday, with Lebanese state media saying he died with six others in a drone strike.

Hezbollah chief Sayyed Hassan Nasrallah on Wednesday described Israel’s killing of Hamas deputy head Saleh al-Arouri in an airstrike in Hezbollah’s stronghold of Beirut’s southern suburbs as “a major and dangerous crime.”

“We cannot overlook it and the matter does not need a lot of talking. It will not remain without a response or punishment and the battlefield and days and nights will prove this,” Nasrallah said, in a televised address marking the third anniversary of the assassination of top Iranian general Qasem Soleimani and top Iraqi militant commander Abou Mahdi al-Muhandis.