As Iran retaliates, largest US military base in Middle East hit by ballistic missile, Qatar says

The CIA had been tracking Iran's Ayatollah Khamenei for months prior to Saturday's U.S.-Israeli attacks on Iran, a source familiar with the intelligence confirmed to ABC News.

When they learned there would be a meeting of top leaders on Saturday with the Supreme leader, the timing of the attack was moved, the source said, adding that the agency had high confidence in their analysis.

These details were first reported by The New York Times. Khamenei was killed in Saturday's attacks.

A second source told ABC News that Israel had been planning for months with its own intelligence to target Iranian leadership, according to a person familiar with the operation.

-ABC News' Cindy Smith and Anne Flaherty

Israeli Prime Minister Benjamin Netanyahu said Israeli forces were "striking the heart of Tehran with increasing strength, which will increase even more in the coming days."

Netanyahu's comments were part of a recorded video message in which said he had "given instructions for the continuation of the campaign" after meeting with senior Israeli officials, including "the minister of defense, the chief of staff and the head of the Mossad," Israel's national intelligence agency.

Netanyahu also said the joint U.S.-Israeli attacks had "eliminated dozens of senior officials of the oppressive regime" in addition to "the dictator Khamenei," referring to Iran's late Supreme Leader Ayatollah Ali Khamenei, who was killed in Saturday's attacks.

He also addressed reports of Israelis killed and injured in retaliatory strikes on Israel, saying "These are painful days. ... My heart goes out to the families."

"We are in a campaign in which we are bringing the entire strength of the IDF, as never before, to this campaign to ensure our existence and our future," Netanyahu said. "But we are also bringing to this campaign the assistance of the United States, my friend, the President of the United States, Donald Trump, the U.S. military. This combination of forces allows us to do what I have been hoping to do for 40 years: to strike the terrorist regime squarely in the face. I promised, and so we will."

-ABC News' Victoria Beaule

Israeli Emergency Services said on Sunday that nine people were killed and 49 were injured in a "missile barrage" in the Beit Shemesh region in central Israel.

A spokesperson for the emergency service, also known as MDA, announced that paramedics were treating casualties after a missile barrage fired at Israel on Saturday and overnight.

The injured were taken to hospitals in Jerusalem and Shamir, including three people in serious condition, three "moderately injured" and 43 "lightly injured," according to the MDA.

Rescue operations were also underway to locate any people who may be trapped in debris from the attacks, according to the Israel Fire and Rescue Service.

-ABC News' Dorit Long and Victoria Beaule

Three U.S. service members were killed and five were "seriously wounded" as part of the attacks on Iran, according to U.S. Central Command.

"As of 9:30 am ET, March 1, three U.S. service members have been killed in action and five are seriously wounded as part of Operation Epic Fury," CENTCOM announced Sunday morning in a post on X.

"Several others sustained minor shrapnel injuries and concussions — and are in the process of being returned to duty," the post continued. "Major combat operations continue and our response effort is ongoing."

The three U.S. fatalities and the other injuries made public by CENTCOM occurred in Kuwait, according to two U.S. officials.

Identities of the service members killed are being withheld "until 24 hours after next of kin have been notified," CENTCOM said, adding that "the situation is fluid."

-ABC News' Luis Martinez