By Jonathan Saul

LONDON, March 18 (Reuters) - A proposal from the UN's shipping agency on Wednesday calls for a safe maritime corridor to free some 20,000 seafarers stranded in the Gulf by war in Iran.

Hundreds of vessels have dropped anchor since Tehran threatened to attack ships attempting to leave the Gulf via the Strait of Hormuz.

The proposal submitted by Bahrain, Japan, Panama, Singapore and the United Arab Emirates and backed on Wednesday by the United States called for "a framework such as a safe maritime corridor".

MADRID, March 18 (Reuters) - Spain plans to evacuate and relocate troops deployed in Iraq in the coming days due to the conflict in Iran and the wider Gulf region, Defence Minister Margarita Robles said on Wednesday.

Around 300 Spanish troops are deployed in Iraq, both as part of an international coalition against the Islamic State formed in 2015 under Operation Inherent Resolve and a separate NATO mission advising Iraqi government forces since 2018.

The upheaval in Iran's leadership since the start of the war with Israel and the United States has further strengthened the political influence of the Islamic republic's ideological army, the Revolutionary Guards, analysts said.

The Islamic Revolutionary Guard Corps (IRGC) was set up on the orders of revolution leader Ayatollah Ruhollah Khomeini shortly after the 1979 ousting of the shah, with a mandate separate from the regular armed forces to protect the revolution from internal and external threats.

WASHINGTON, March 18 (Reuters) - The White House said on Wednesday that China had agreed to postpone U.S. President Donald Trump's visit to Beijing, originally scheduled in just two weeks.

Spokeswoman Karoline Leavitt said that the White House was working to secure a new date for the visit as soon as possible.

Trump, citing the demands of the Iran war, said on Tuesday that he would take the trip to Asia in "about five or six weeks" but did not specify a date.

DUBAI, March 18 (Reuters) - Facilities belonging to Iran's oil industry in South Pars and Asaluyeh were attacked on Wednesday, Iranian state media said, prompting Tehran to warn that it would target energy installations across Saudi Arabia, the United Arab Emirates and Qatar.

Oil prices jumped on the news, with Brent crude futures gaining more than 6% to a session high just shy of $110 per barrel. Analysts have warned that any attack in South Pars would raise the possibility of retaliatory attacks by Iran on Gulf energy facilities including those belonging to oil majors in Qatar.

US intelligence concluded Wednesday that Iran was not rebuilding nuclear enrichment capacities destroyed last year by the United States and Israel, contradicting a key justification by President Donald Trump for his ongoing war.

Tulsi Gabbard, a Trump ally who is director of national intelligence, offered mixed signals on the backdrop and outcomes of three weeks of war as she and other officials appeared before Congress

She also assessed that Iran's leadership remained intact.

LONDON, March 18 (Reuters) - Britain's national security adviser, Jonathan Powell, was not part of final talks between the United States and Iran before the U.S. and Israel launched strikes against Tehran, a spokesperson for Prime Minister Keir Starmer said on Wednesday.

Britain's Guardian newspaper reported on Tuesday that Powell had attended the talks and judged the offer made by Tehran on its nuclear programme significant enough to prevent a rush to war.

By Steven Scheer

TEL AVIV, March 18 (Reuters) - Iran has launched dozens of missiles with cluster munition warheads at Israel since the start of the war, posing a challenge for Israel's missile defence shield as they need to be hit before they split and disperse into smaller explosives.

Israel failed to intercept one of the cluster missiles overnight, and its small bomblets scattered into civilian areas in Tel Aviv. A couple in their 70s was killed, and one of Tel Aviv's main train stations suffered damage.

By Alessandro Parodi

March 18 (Reuters) - As Emirates flight EK10 from London cruised over Saudi Arabia on Monday, news broke of a drone strike at its destination, Dubai. The aircraft turned back to Gatwick, flight data show, completing a 9,100 km (6,150 miles) round trip — one of dozens of "flights to nowhere" triggered by the Middle East war.

Roughly 30 Emirates flights heading to Dubai International were also ordered back or rerouted after Iranian drone attacks temporarily shut what is normally the world's busiest airport for international passengers.

US President Donald Trump's administration scrambled Wednesday to rein in surging energy costs from war in the Middle East, temporarily waiving a century-old shipping law and easing Venezuela sanctions.

The moves came after oil prices rocketed following US-Israeli strikes on Iran on February 28. Tehran's retaliation brought commercial shipping through the Strait of Hormuz to a virtual halt, snarling energy supply chains.