By The South Asia Times

TEHRAN - Thick plumes of smoke rose over the Iranian capital Saturday morning as heavy explosions echoed across Tehran following a coordinated joint military attack by the United States and Israel, plunging the Middle East into a new and dangerous confrontation, according to Iranian and Israeli media.

Israeli media, citing security sources, confirmed the operation was a "joint Israeli-American attack" that had been planned for months, with the launch date finalised weeks ago. A US official later confirmed to multiple news agencies that American forces were actively participating in the strikes alongside Israel.

Iranian media and witnesses reported missiles striking multiple districts in central Tehran, including University Street and Jomhouri, with visible smoke rising from the city.

Reports indicated that explosions occurred near the offices of Iran's Supreme Leader Ayatollah Ali Khamenei, though his whereabouts remained unconfirmed.

According to sources cited by Reuters, the 86-year-old Supreme Leader was not in Tehran at the time of the attack and had been transferred to a secure location.

Khamenei had not been seen publicly in recent days amid growing tensions with the United States.

The strikes extended beyond the capital, with explosions also reported in Isfahan, Qom, Karaj, Kermanshah, and the north-western city of Tabriz. 

According to Iranian officials, several locations in the city were targeted, including the ministries' buildings.

Israel's Defence Minister Israel Katz confirmed the operation, describing it as a "pre-emptive strike against Iran to remove threats to the State of Israel". Shortly after the attacks began, Israel declared a nationwide state of emergency and closed its airspace to all civilian flights .

Iran also shut down its airspace entirely, forcing civilian and commercial flights to be halted or rerouted.

The dramatic escalation followed stark warnings from US President Donald Trump just one day earlier. Speaking to reporters on Friday, Trump expressed deep dissatisfaction with the progress of nuclear negotiations with Iran, which had been mediated by Oman in Geneva.

On Friday, speaking at an event in Texas, Trump framed the choice facing his administration in stark terms: "We have a big decision to make" on whether to attack Iran, describing the choice as "not easy".

The strikes follow the largest US military build-up in the Middle East since the 2003 invasion of Iraq. The USS Gerald R. Ford arrived off Israel's coast on Friday, joining the USS Abraham Lincoln, which has been operating in the Arabian Sea since late January, along with two aircraft carrier strike groups, additional fighter squadrons, and refuelling aircraft.

On Friday, the US ordered its embassy staff in Israel to leave the country as soon as possible, with Ambassador Mike Huckabee advising staff who wished to leave to "do so TODAY". Multiple countries, including China, the UK, Germany, France, India, and Canada, had also urged their citizens to leave Iran due to the prospect of hostilities.

* This is a developing story