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

Iran's parliament speaker, Mohammad Bagher Qalibaf, said in a speech on Sunday morning that the U.S. and Israel had crossed a red line in launching their attacks on Iran, vowing strong retaliation.

In his speech, which was broadcast on Iranian state television, Qaribah also addressed Iranian protesters directly, acknowledging their legitimate concerns but adding that no one should side with Iran's enemies.

Qalibaf said that the heart of the Iranian nation was broken after the death of Ayatollah Ali Khamenei and pledged that the path he forged would continue.

ABC News' Somayeh Malekian and Ellie Kaufman

In a new post on his social media platform Sunday morning, President Donald Trump warned Iran not to escalate its attacks, following U.S. strikes against the country.

"Iran just stated that they are going to hit very hard today, harder than they have ever hit before," Trump wrote in the post. "THEY BETTER NOT DO THAT, HOWEVER, BECAUSE IF THEY DO, WE WILL HIT THEM WITH A FORCE THAT HAS NEVER BEEN SEEN BEFORE!"

The Iranian Revolutionary Guard Corps took responsibility for targeting 27 US bases in the Middle East region in a statement broadcast by Iranian state media Sunday morning.

Sirens were sounding in Bahrain at about 8 a.m. local time, Bahraini state TV confirmed.

In addition to the bases, the IRGC statement said it was targeting the large defense industrial complex in Tel Aviv.

The following three officials will act collectively as a temporary leadership council to govern Iran, Iranian state media reported.

The three individuals that will form the council are the Iranian President Masoud Pezeshkian, the Iranian Judiciary Chief Gholamhossein Mohseni Ejei, and a jurist from the Guardian Council, Iranian state media said.