Israel-Gaza-Lebanon updates: Iranian president responds to Israel's retaliatory attacks

Secretary of State Antony Blinken will begin a tour of Israel and other Middle Eastern nations on Monday in a bid to inject new life into stalled cease-fire and hostage release negotiations in Gaza, the State Department said.

Blinken "will discuss the importance of bringing the war in Gaza to an end, securing the release of all hostages and alleviating the suffering of the Palestinian people," the State Department notice said.

"He will continue discussions on post-conflict period planning and emphasize the need to chart a new path forward that enables Palestinians to rebuild their lives and realize their aspirations free from Hamas' tyranny," the statement said.

Blinken will also "underscore that additional food, medicine and other humanitarian aid must be delivered to civilians in Gaza," it continued.

The situation in Lebanon -- where Israel is continuing an intense air and ground campaign and Hezbollah is still firing across the shared border -- will also be a topic of discussion, the State Department said.

Blinken will continue pursuit of a "diplomatic resolution" that "allows civilians on both sides" of the border to return to their homes, the statement said.

-ABC News' Cindy Smith

"Beirut in flames," Israeli Foreign Minister Israel Katz wrote on X on Monday following an intense night of airstrikes on the Lebanese capital.

"A wide-scale Israeli attack targeted Hezbollah's financial infrastructure in Beirut and across Lebanon last night," Katz said.

"Massive fires were seen above Beirut as over 15 buildings were struck following evacuation warnings to residents," the foreign minister wrote.

"Hezbollah has paid and will continue to pay a heavy price for its attacks on northern Israel and its rocket fire. We will keep striking the Iranian proxy until it collapses."

-ABC News' Guy Davies

Israel Defense Forces warplanes launched "a series of targeted, intelligence-based strikes against dozens of facilities and sites used by the Hezbollah terrorist organization to finance its terrorist activities," the IDF said in a Monday post to X.

The Sunday night strikes hit targets in Beirut, southern Lebanon and elsewhere "deep within" the country, the IDF added.

The IDF said the targets were linked to the Al-Qard Al-Hassan Association, which Israel has accused of acting as a key financier of Hezbollah activities.

-ABC News' Jordana Miller

Documents purporting to show classified U.S. intelligence-gathering on Israel's preparations for a possible retaliatory strike against Iran appeared on social media platforms late last week.

The impact of the circulation of these documents on current and future planning by the Israeli military is unclear at this time.

U.S. officials declined to comment on the situation when reached by ABC News. However, a law enforcement source on Sunday confirmed with ABC News that there is an investigation underway.

Markings on the documents indicate that they would have originated from the National Geospatial-Intelligence Agency, which collects, analyzes and distributes intelligence gleaned from satellite and aerial imagery.

If the documents are authentic, it would indicate a major intelligence breach.

According to Mick Mulroy, an ABC News national security and defense contributor, who served as the deputy assistant secretary of defense for the Middle East: "The future coordination between the U.S. and Israel could be challenged, as well."

The Department of Defense, Federal Bureau of Investigation and a spokesperson for the Office of the Director of National Intelligence all declined to comment when contacted by ABC News.

House Speaker Mike Johnson appeared on CNN Sunday and acknowledged that there is an investigation underway into the possible intelligence leak, adding, "We're following it closely."

-ABC News' T. Michelle Murphy