The US-Israeli conflict against Iran expanded on Monday with no end in sight, engulfing Lebanon with Israel responding to strikes by Hezbollah, while Tehran fired missiles and drones at Israel, Gulf states and a UK air base in far-away Cyprus.

Several explosions have been heard in Iran's capital Tehran, according to the country's Tasnim news agency. The report said "the air strike targeted an area near Revolution Square where demonstrators were gathered in a rally condemning the aggression."

"Iranian air defenses intercepted the attack in the skies over central Tehran," it added.

The Israeli army says its air force has begun "an additional broad strike" in central Tehran, targeting the government.

Video images showed a US warplane falling out of the sky over Kuwait early on Monday, while a person could be seen parachuting. The location was verified by Reuters as filmed in the Al Jahra area of Kuwait. 

Kuwait's defense ministry said several American aircraft had crashed and all crew were safe, while the US reported so-called 'friendly fire' caused the crashes.

Energy prises surge

After a weekend of bombing that killed Iran's supreme leader, dragged its neighbors into conflict and shut shipping traffic in the Gulf, markets opened on Monday with energy prices rising sharply, putting the global economic recovery at risk.

State oil giant Saudi Aramco's Ras Tanura refinery was shut after a drone strike as a precautionary measure. It is part of an energy complex on the kingdom's Gulf coast which also serves as a critical export terminal for Saudi crude oil.

Two drones were intercepted at the facility, with debris causing a limited fire, the Saudi defense ministry's spokesperson said on Al Arabiya TV, adding there were no injuries.

US President Donald Trump, who launched the campaign alongside Israel, repeated his calls on Iranians to rise up and overthrow their leaders, and said the air campaign could last weeks. Within Iran, where residents have jammed highways to flee cities as bombs fell, there was uncertainty about the future.

Civilians killed

Iran declared 40 days of mourning after the killing of Supreme Leader Ayatollah Ali Khamenei who ruled the country for 37 years and directed security forces that killed thousands of anti-government protesters at the start of this year.

But the conservative clerical leaders have shown no sign of yielding power. Military experts say US and Israeli air power, with no armed force on the ground, may not be enough to drive them out. And meanwhile scores of Iranians have been reported killed in strikes, including several that hit apparent civilian targets.

"They are killing children, they are attacking hospitals. Is this the kind of democracy Trump wants to bring us? Innocent people were first killed by the regime and now by Israel and the United States," Morteza Sedighi, a 52-year-old teacher, said by phone from Tabriz.

A major new front in the conflict opened when Hezbollah, one of Tehran's principal allies in the Middle East, launched missiles and drones toward Israel in retaliation for the killing of Khamenei.

Israel responded with sweeping airstrikes, which it said targeted the Hezbollah-controlled southern suburbs of Beirut and struck senior officials. Lebanese state news agency NNA said an initial tally showed 31 people had been killed and 149 injured.

Lebanon bans Hezbollah's military wing

Israel declared Hezbollah leader Naim Qassem a "target for elimination." However, Israeli officials said they were not considering a ground invasion of Lebanon for now.

The Lebanese government has imposed an "immediate ban" on Hezbollah's military and security activities and called on the group to hand over its weapons to the state, Prime Minister Nawaf Salam announced.

Inside Iran, explosions were heard across Tehran, while in Israel air raid sirens were triggered in Tel Aviv and Jerusalem.

Washington's allies in the Gulf have come under attack from Iranian missiles and drones. Black smoke rose above the area around the US embassy in Kuwait, where there was a heavy presence of security, ambulances and fire trucks. 

There were loud blasts in Dubai and Samha in the UAE, and in Doha, capital of Qatar.

China condemns attacks

The conflict has killed one Chinese citizen in capital Tehran, while more than 3,000 were evacuated, China's foreign ministry said, as its embassies and consulates in nearby countries swung into action to help the affected.

Work groups set up by Chinese embassies and consulates in neighboring countries will receive and assist those evacuated, ministry spokesperson Mao Ning told a regular press briefing. She reiterated condemnation of the attacks and the killing of Khameini, urging all parties involved to immediately cease military action to prevent escalation.

Jia Guide, China's ambassador to the United Nations, told the UN Human Rights Council in Geneva that the attacks against Iran and killing of the Iranian leader violated the principles of the UN Charter and the human rights of Iranians.

In the first strike to reach US allies in Europe, a drone hit Britain's Akrotiri air base in Cyprus overnight. The UK and Cyprus said the damage was limited and there were no casualties. 

European allies have so far distanced themselves from Trump's decision to attack Iran, which the UK, France and others say fell short of the legal threshold of combating an imminent threat.

UK Prime Minister Keir Starmer said his country would not join the US-Israeli conflict with Iran, saying that mistakes of the Iraq war had been "learned", but announced late on Sunday that he had agreed to the United States' request to use British bases for "specific and limited defensive purposes."

The Israeli military said that its air force had established aerial superiority over Tehran, and that a wave of strikes across the capital had targeted intelligence, security, and military command centers.

A source briefed on the Israeli operation said strikes so far have been significantly more intense and extensive than 12 days of strikes last June. Another wave of Israeli reservists would be called up in the next 48 hours, the source said.

Trump's 'delusional ambitions'

In interviews on Sunday, Trump said the campaign could last four weeks. A senior White House official told Reuters that Washington would at some point talk with Tehran's leaders, but not yet.

Iran's elected president, Masoud Pezeshkian, said on Sunday a leadership council composed of himself, the judiciary head and a member of the powerful Guardian Council had temporarily assumed the duties of supreme leader.

In an X post on Monday, Ali Larijani, a powerful adviser to Khamenei, said his country would not negotiate with Trump. He said the US president had "delusional ambitions" and was now worried about US casualties.

The first US casualties of the campaign, including the deaths of three service personnel, were confirmed on Sunday. Two US officials told Reuters they were killed on a base in Kuwait. Trump paid tribute to them as "true American patriots."

In a video posted on Sunday, Trump vowed military strikes on Iran would continue until "all our objectives are achieved" without providing specifics.

Trump called on Iran's military and police, including the Islamic Revolutionary Guards Corps, to stop fighting, promising immunity for those who surrender and "certain death" for those who resist. He reiterated calls for Iranians to rise up.

Meanwhile, the interruption to oil shipments through the Strait of Hormuz - where around a fifth of the world's oil trade passes along the Iranian coast – was a sudden jolt to global economies. Oil prices leapt by double-digit percentages when trade opened on Monday. Shares fell and the dollar surged.

Iran's Revolutionary Guards said they had hit three US and UK oil tankers in the Gulf and the Strait of Hormuz and attacked military bases in Kuwait and Bahrain with drones and missiles. Shipping data showed hundreds of vessels including oil and gas tankers dropping anchor in nearby waters.

Global air travel was also heavily disrupted as air strikes kept major Middle Eastern airports closed, including Dubai, the world's busiest international hub.