Lebanese official media said Monday people were receiving Israeli phone warnings telling them to evacuate, and Information Minister Ziad Makari's office told AFP it had received one of the calls.

"Citizens in Beirut and a number of areas are receiving landline telephone warning messages whose source is the Israeli enemy, asking them to quickly evacuate where they are," the Lebanon's official National News Agency (NNA) said.

Lebanon's health ministry said three people were killed in separate Israeli strikes on south Lebanon on Sunday, as Israel said it was striking Hezbollah targets in Lebanon.

In separate statements, the health ministry said one person was killed in Israeli strikes in three different south Lebanon villages.

Israeli Prime Minister Benjamin Netanyahu said on Sunday that Israel had "landed a series of blows on Hezbollah" after a night of intense cross-border fire and attacks this week in Lebanon.

"In recent days, we have landed a series of blows on Hezbollah that it could have never imagined. If Hezbollah did not get the message, I assure you it will get the message," Netanyahu said in a statement.

The Israeli defense minister says the steps taken against Hezbollah will continue until residents of Israel’s north can return to their homes, saying "we will do everything necessary to achieve it.”

Yoav Gallant was on a visit to the command and control center of the Israeli Air Force when he said Hezbollah “has started to sense some of the capabilities" of the Israeli army and that Hezbollah is now feeling "persecuted, and we are seeing the results.”

The U.S. State Department has urged Americans in Lebanon to leave the country while commercial options remain available, as the conflict between Israel and Hezbollah flares.

"Due to the unpredictable nature of ongoing conflict between Hezbollah and Israel and recent explosions throughout Lebanon, including Beirut, the U.S. Embassy urges U.S. citizens to depart Lebanon while commercial options still remain available," the State Department said in an updated advisory.

Germany has said there is an "urgent need" for measures to calm tensions in the Middle East as Israel's war on Hamas in Gaza threatened to spread to Lebanon.

Attacks carried out by Israel or blamed on it, including air strikes and the explosions of hand-held communications devices, have killed dozens and injured thousands in Lebanon since Tuesday.

The death toll from the Israeli air strike that targeted Hezbollah military commanders in Beirut's southern suburbs and killed scores of civilians this week has risen to 45, Lebanon's health ministry said Sunday.

The United Nations special coordinator for Lebanon warned Sunday of an "imminent catastrophe" in the Middle East amid spiking violence between Israel and Lebanon's Hezbollah, saying a military solution was not the answer.

The Israeli military said more than 100 projectiles were fired early Sunday from Lebanon, forcing hundreds of thousands to take cover and prompting school closures in Israel's north.

The military said that "approximately 20 projectiles were identified crossing from Lebanon" shortly before 5:00 am (0200 GMT), followed by a barrage of "approximately 85 projectiles" launched from Lebanon after 6:00 am (0300 GMT).

Hezbollah said it targeted military production facilities and an air base in northern Israel on Sunday in an "initial response" to the pager and walkie-talkies explosions and in response to Israeli attacks that killed civilians in various parts of Lebanon.

"In an initial response" to the explosions of pagers and two-way radios on Tuesday and Wednesday, Hezbollah "bombed the Rafael military industry complexes" north of Haifa with "dozens" of Katyusha, Fadi-1 and Fadi-2 rockets, the group said.