State Department tells Americans worldwide to 'exercise increased caution'

Israel said its forces were planning to strike bridges across Lebanon's Litani River, warning people living south of that river and the farther north Zahrani River to evacuate to the north immediately.

"For your safety and the safety of your families, immediately move to areas north of the Litani River," the Israel Defense Forces said on social media on Wednesday. "Remaining south of the Litani River may endanger your lives and the lives of your families. Please note: any movement southward may endanger your lives."

Israel said it was being "compelled" to carry out the strikes because of Hezbollah's activities "with the support of the civilian population."

"Accordingly, and to prevent the transfer of reinforcements and combat means, the Defense Army intends to attack crossings on the Litani River starting from midday hours today," Avichay Adraee, a spokesperson for the Israel Defense Forces said, said on social media.

The expected bridge strikes would come as Israeli forces escalate their aerial and on-the-ground assaults against purported Hezbollah infrastructure in Southern Lebanon, which is south of the river, and in Beirut, the capital.

It was unclear how civilians remaining in the south would be able evacuate to the north if river crossings were destroyed.

-ABC News’ Ghazi Balkiz

An overnight Israeli strike on Iran killed Esmail Khatib, the intelligence minister, according to the Israeli defense minister.

Israel Katz, the defense minister, said Wednesday that Khatib had been in charge of "the regime's internal murder and repression system in Iran and of promoting external threats."

Announcing this latest killing, Katz said that "significant surprises are expected in all arenas" which will escalate the war against Iran and Hezbollah in Lebanon, without disclosing details.

-ABC News' Somayeh Malekian and Jordana Miller

At least six people were killed and 24 others were injured in early morning Israeli strikes on Beirut, the Lebanese health ministry said, as Israel said it struck Hezbollah-related infrastructure in both the capital and the country's south.

The Lebanese ministry said Beirut had been strike twice on Wednesday morning. At least one building in the city was levelled.

The Israel Defense Forces said in a statement that Hezbollah, the Iranian proxy operating in Lebanon, had fired "dozens" of rockets toward Israel.

The IDF said it responded to those rockets by warning residents of Tyre, a southern coastal city, of impending strikes. Strikes on the city then destroyed what Israel described as a weapons-storage facility.

Israel said it also targeted in Beirut "additional assets" of the Al-Qard Al-Hassan Association, a group said to help finance Hezbollah’s operations.

"Alongside headquarters of the 'Hamasin' Division in southern Lebanon that were struck from the air and sea, the Navy struck a key terrorist in the Hezbollah terror organization in Beirut," the IDF said in a statement early on Wednesday. "Prior to the strike, steps were taken to minimize the chance of harm to civilians, including advance warnings, use of precision munitions, and aerial observations."

Israel said its military intends to "continue to act forcefully against the Hezbollah terror organization, which decided to join the campaign and operate under the auspices of the Iranian terror regime, and will not allow harm to civilians of the State of Israel."

Officials in Saudi Arabia, Qatar, Kuwait and the United Arab Emirates said early on Wednesday they were working to intercept Iranian drones or missiles.

"Kuwaiti air defense systems are currently engaged in intercepting hostile missiles and drones that breached the country's airspace," the official Kuwait News Agency said.

The UAE was responding to incoming missile and drone threats from Iran, officials there said, adding, "MOD asserts that the sounds heard are the result of the Air Defense Systems intercepting missiles and drones."

Qatar said it was countering a missile attack. The Saudi Ministry of Defense said in a series of updates that it was attempting to down hostile drones, several of which were aimed at its Eastern Province, where much of the country’s oil production takes place.