U.N. peacekeepers claim IDF tanks breached their base in southern Lebanon.
The Israel Defense Forces continued intense air and ground campaigns against Hezbollah in Lebanon and against Hamas in the Gaza Strip.
The uptick in offensive operations came days after Israel marked the anniversary of Hamas' Oct. 7 assault and as Israeli leaders planned their response to last week's Iranian ballistic missile attack.
In a warning to vacationers, beachgoers and boaters, the Israel Defense Forces said they will soon operate against "Hezbollah maritime targets" south of the Awali River line.
"For your safety, refrain from being in the sea or on the beach from now until further notice. Being on the beach and boat movements in the area of the Awali River line southward pose a danger to your life," the IDF said.
President Joe Biden and first lady Jill Biden joined a memorial candle lighting held Monday in the Blue Room of the White House in remembrance of the victims of the Oct. 7 attack.
Rabbi Aaron Alexander recited in Hebrew "El Malei Rachamim" ("God Full of Mercy"), a traditional Jewish prayer for those who have died, then recited it in English.
Biden then lit the yahrzeit candle before observing a moment of silence. Biden made the sign of the cross after a few moments.
Alexander is a family friend of the Goldberg-Polin family. American-Israeli Hersh Goldberg-Polin, 23, was taken hostage by Hamas on Oct. 7 at the Nova Music Festival. His body was recovered by Israeli forces in late August.
Biden also spoke with Israeli President Isaac Herzog earlier Monday to express his "deepest condolences" to Israelis and families of the Oct. 7 attack, the White House said.
-ABC News' Justin Ryan Gomez
Air alert sirens sounded across central Israel on Monday due to a missile launch from Yemen, the Israel Defense Forces said.
"The air force successfully intercepted a surface-to-surface missile launched from Yemen," the force wrote on X.
Iran-aligned Houthi rebels in Yemen have repeatedly targeted Israel using missiles and drones. Israel has launched airstrikes on Houthi military and infrastructure sites in response.
Two more powerful strikes hit Beirut on Monday morning as Israel's air campaign continued, including one that impacted close to the city's international airport.
The strikes sent towering pillars of smoke and dust rising above the capital and Beirut-Rafic Hariri International Airport.
The airport is located south of the city center close to the Dahiya suburb, which is known as a Hezbollah stronghold and has borne the brunt of Israel's attacks on the city.
Beirut's airport is still functioning despite nearby airstrikes, though major international carriers have frozen operations there due to the deteriorating security situation.
Lebanon-based Middle East Airlines now accounts for most flights landing at and departing the airport, which was bombed by Israeli warplanes in 2006 during the last major cross-border conflict.
-ABC News' Patrick Reevell and Morgan Winsor
