He is the son of assassinated Supreme Leader Ayatollah Ali Khamenei.
President Donald Trump announced "major combat operations" against Iran on Feb. 28, with massive joint U.S.-Israel strikes attack targeting military and government sites, officials said.
Iranian state television confirmed that Ayatollah Ali Khamenei was among those killed by airstrikes in Tehran on the first day of strikes. His successor is yet to be named.
Iran is responding to the operation with missile and drone attacks targeting Israel, regional U.S. bases and multiple Gulf nations. Israel is also intensifying its long-running strike campaign against the Iran-backed Hezbollah militia in Lebanon.
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Strikes from Iran were continuing in Bahrain Sunday night into Monday morning, according to the country's interior ministry.
Officials said injuries among citizens were reported, with one of them being serious. The number of those injured was not released.
The interior ministry said a number of houses in Sitra were damaged in the drone attacks.
Mojtaba Khamenei, the second-oldest son of assassinated Iranian Supreme Leader Ayatollah Ali Khamenei, has been chosen as the next supreme leader of Iran, according to Iranian state media.
He has become the third leader of the Islamic Revolution of Iran by the vote of the Assembly of Experts, state media reported Sunday.
Mojtaba, 56, has long been viewed by analysts as a possible successor to Khamenei, who was killed last Saturday by a series of airstrikes in Tehran in the opening salvos of the U.S.-Israeli campaign.
Analysts have broadly characterized Mojtaba as a powerful figure with limited public and international profiles, operating somewhat behind the scenes but enjoying major influence.
Iran's Air Force headquarters were targeted during wide-scale Israeli military strikes on dozens of Iranian regime facilities, according to the Israel Defense Forces (IDF).
The headquarters, according to the IDF, was the main command-and-control center used to direct the Islamic Revolutionary Guard Corps' air force activity, including the regime's ballistic missile command, its unmanned aerial vehicle fleet and other air force units.
"The Air Force Headquarters was also responsible for producing a situational picture and for planning missile attacks on the State of Israel and the countries in the region," the IDF said.
-ABC News' William Gretsky
Israel Defense Forces (IDF) said Sunday that it killed five Iranian senior commanders of Iran's Islamic Revolutionary Guard Corps (IRGC) in a strike on a hotel in Beirut, Lebanon.
The commanders were targeted by the Israeli Navy, according to the IDF. The commanders were part of the IRGC's Quds Force’s Lebanon Corps, which serves as a central liaison between the Hezbollah terrorist organization and the Iranian regime, the IDF said.
"Its senior officials synchronize activities across the various terrorist organizations operating in Lebanon. The commanders eliminated in the strike were advancing terrorist activity across Lebanon while hiding in a civilian hotel," the IDF said.
The commanders were targeted following the elimination of the commander of the Lebanon Corps, Daoud Ali Zadea, last week, the IDF said.
-ABC News' Dorit Long
