The Israeli military declared a military zone in parts of its northern border with Lebanon on Monday ahead of possible ground operations.

"The areas of Metula, Misgav Am, and Kfar Giladi in northern Israel have been declared a closed military zone. Entry to this area is prohibited," the military said in a statement.

United Nations peacekeepers in Lebanon have been unable to conduct patrols because of the intensity of Israeli strikes and Hezbollah’s rockets targeting Israel, a U.N. spokesman said Monday.

"Our UNIFIL Blue Helmets remain in position in the mission’s area of responsibility, while the intensity of fighting is preventing their movements and ability to undertake their mandated tasks," Stephane Dujarric, spokesman for U.N. Secretary-General Antonio Guterres, told a media briefing.

Israel has informed the United States about limited ground operations targeting Hezbollah infrastructure inside Lebanon, the State Department said Monday.

"I've seen reports about ground operations. We've had some conversations with them about that; they have at this time told us that those are limited operations focused on Hezbollah infrastructure near the border," State Department spokesman Matthew Miller told journalists.

Germany sent an air force plane to strife-torn Lebanon on Monday to fly out some Beirut embassy staff and their dependents as well as German citizens with medical conditions, the government said.

"An Air Force A321 aircraft flew to Beirut today to support the departure of the colleagues and their families," said a joint statement by the foreign and defense ministries. "German nationals who are particularly at risk due to medical circumstances are also being taken on the Bundeswehr aircraft."

The world is safer after Israel's killing of Hezbollah chief Sayyed Hassan Nasrallah, the top U.S. diplomat said Monday, describing the Iran-backed Lebanese group's leader as a "brutal terrorist."

"The region, the world are safer without him," Antony Blinken said, even as he insisted that "diplomacy remains the best and only path to achieving greater stability in the Middle East" and vowed the United States would continue working "urgently" to secure a ceasefire between Israel and Palestinian militant group Hamas in Gaza.

Israeli Prime Minister Benjamin Netanyahu on Monday warned Iranians there was no place in the Middle East beyond Israel's reach, as his military launched strikes on the Iran-backed Hezbollah in Lebanon.

"There is nowhere in the Middle East Israel cannot reach," Netanyahu said in a video statement issued in English, warning the people of Iran that their "regime plunges our region deeper into darkness and deeper into war".

The Israeli military said on Monday its forces killed at least two leaders of a left-wing Palestinian armed group, hours after the organization said its members were hit in a strike in central Beirut.

Israeli fighter jets "struck and eliminated the terrorist" Mohammad Abdel-Aal, head of the Lebanon branch of the Popular Front for the Liberation of Palestine (PFLP), the military said in a statement.

Lebanon's health ministry said an Israeli strike Monday killed six rescuers with the Hezbollah-affiliated Islamic Health Committee in the Bekaa Valley in the country's east.

An "enemy strike on the civil defense center of the Islamic Health Committee killed six emergency personnel and wounded four others" in the town of Sohmor, the ministry in a statement, condemning Israel's "targeting of rescue services".

Lebanon said Monday that an Israeli strike a day earlier near the southern city of Sidon killed 45 people, raising an earlier toll.

In a statement, the health ministry announced "45 dead and 70 wounded in an updated toll for the Israeli enemy attack on Ain al-Delb" on Sunday, while the official National News Agency said the strike targeted a building which completely collapsed.

Iran will not deploy forces to Lebanon or Gaza to confront Israel, its foreign ministry said on Monday, as Israeli strikes target its allies in the region.

"There is no need to send extra or volunteer forces of the Islamic Republic of Iran," said foreign ministry spokesman Nasser Kanani, adding that Lebanon and fighters in the Palestinian territories "have the capability and strength to defend themselves against the aggression."