Israeli forces chose to carry out the strike in Lebanon that killed Hezbollah chief of staff Haitham Ali Tabataba'I on Sunday as a “contained, opportunity-based elimination,” an Israeli military official said Monday.

Israel “chose to carry out the strike now after identifying a clear window of opportunity to target a key terrorist in the organization,” the official said. “There is no intention to escalate. This is a contained, opportunity-based elimination.”

Israeli forces have been striking targets in southern Lebanon they say are associated with Hezbollah in October and November since the Israel-Hamas ceasefre went into effect. This is the first time Israel has struck Beirut, Lebanon’s capital, since June.

-ABC News' Jordana Miller and Ellie Kaufman

The controversial U.S.- and Israel-backed Gaza Humanitarian Foundation will end its operations, the organization said in a statement to journalists Monday.

GHF began operating in May 2025 after Israel lifted an 11-week total humanitarian aid blockade on Gaza.

GHF has not been operating since the start of the ceasefire, but the organization officially announced it would be closing its operations on Monday.

“With the end of its operations, GHF leadership states that the organization will remain on standby to resume operations should new humanitarian needs arise, and will not be dissolved as a registered NGO,” GHF said.

GHF had four operational sites inside Gaza throughout the course of its operations. These sites and GHF’s operations were heavily criticized by international aid organizations. Instances of people dying trying to get aid at these sites were also reported.

-ABC News' Jordana Miller and Ellie Kaufman

The Israel Defense Forces said in a post to social media on Monday that its warplanes attacked three fighters it alleged crossed the yellow line in the southern Gaza Strip at which Israeli forces are now positioned.

The three individuals "approached IDF forces operating in the area in a manner that posed an immediate threat to them," the IDF said.

"After the identification, the air force, under the direction of the forces in the field, attacked the three terrorists in order to eliminate the threat," the IDF wrote. "Hits were identified."

Lebanese President Joseph Aoun said in a statement issued by his office that Israel's strike in Beirut on Sunday was "further proof that it disregards repeated calls to cease its attacks on Lebanon and refuses to implement international resolutions and all efforts and initiatives aimed at ending the escalation and restoring stability, not only to Lebanon but to the entire region."

"Lebanon, which has adhered to the cessation of hostilities for nearly a year now and has presented initiative after initiative, reiterates its call to the international community to assume its responsibility and intervene firmly and seriously to stop the attacks on Lebanon and its people," Aoun said.

Israeli Prime Minister Benjamin Netanyahu's office said Sunday that Hezbollah chief of staff Haitham Ali Tabataba'i was the target of the strike in the south of the capital, which the Lebanon Health Ministry said killed a total of five people and injured 28.

Hezbollah confirmed that Tabataba'i was among those killed.

Despite the ceasefire agreement signed with Hezbollah last November, Israel has continued bombing targets across Hezbollah-dominated areas in southern and eastern Lebanon. Israeli soldiers are also still deployed at five locations inside southern Lebanon.

The Israeli strike in Beirut on Sunday was the first attack on the Lebanese capital for several months.