Iran's consulate in the Syrian capital Damascus was flattened on Monday in what Syrian and Iranian media described as an Israeli air strike.
A Lebanese security source, speaking to Reuters, said one of the dead was Mohammad Reza Zahedi, a senior commander in Iran's Revolutionary Guards Corps (IRGC). Iranian state television said several Iranian diplomats had been killed.
Israel, which has repeatedly hit Iranian targets during the six-month war in Gaza, declined to comment on the incident, following its usual practice.
An Israeli military spokesperson said: "We do not comment on reports in the foreign media."
Iran's Tasnim news agency said five people were killed in the Israeli strike. Syria's SANA state news agency reported an unspecified number of deaths and injuries.
Since the Palestinian group Hamas' attack on Israel on October 7, Israel has ramped up airstrikes in Syria against Lebanon's Hezbollah militia and Iran's Guards, both of which support the government of President Bashar Al Assad.
The Federal Aviation Administration (FAA) halted traffic on Monday at busy US East Coast airports, snarling more than 1,000 flights after a telecom circuit failed and a backup fibre cable was accidentally cut.
MS NOW, CNN and Politico said on Monday they were suing the Trump Administration to protect their First Amendment rights after President Donald Trump's announcement that he would ban the news outlets from the White House's building grounds.
Pakistan's government said on Monday that it launched airstrikes in the Afghanistan-Pakistan border region, killing at least 28 militants, with one security official saying two Afghan provinces were targeted.
Flights at several British airports were delayed on Monday due to an air traffic control failure, Britain's NATS air traffic control provider said, less than two weeks after a separate issue halted flights across the country.
A fire that broke out at a textile factory in the Chinese city of Foshan in southern Guangdong province on Sunday killed eight people and injured one, state media said on Monday.