* Yemen had, until now, stayed out of the Iran war

* First contingent of US Marine deployment arrives in

Middle East

* Washington Post reports US preparing for weeks of

ground operations

* Iranian attack on base in Saudi Arabia injures 12 US

service personnel

By Menna AlaaElDin and Nayera Abdallah

CAIRO/DUBAI, March 29 (Reuters) - The risk of an

expanded Iran war grew as Yemen's Iran-aligned Houthis on

Saturday launched their first attacks on Israel since the start

of the conflict, even as additional U.S. forces reached the

Middle East.

Washington has dispatched thousands of Marines to the Middle

East. The first of two contingents arrived on Friday on an

amphibious assault ship, the U.S. military said on Saturday.

On Saturday, the Washington Post reported U.S. officials

said the Pentagon is preparing for weeks of ground operations in

Iran. Whether President Donald Trump would approve plans for

deploying ground troops remained uncertain, the Post reported.

The war, launched on February 28 with U.S. and Israeli

strikes on Iran, has spread across the Middle East, killing

thousands and hitting the world economy with the biggest-ever

disruption to global energy supplies.

On Friday, Secretary of State Marco Rubio said the U.S.

could achieve its aims without ground troops. But he

acknowledged it was deploying some to the region so Trump would

have "maximum" flexibility to adjust strategy.

The Pentagon was also expected to deploy thousands of

soldiers from the U.S. Army's 82nd Airborne Division.

Iranian President Masoud Pezeshkian spoke to Pakistan's

Prime Minister Shehbaz Sharif, whose government hosts a meeting

with the Turkish and Saudi foreign ministers on Sunday to seek

to ease regional tensions.

LEBANESE JOURNALISTS, RESCUE WORKERS HIT

On Saturday, Israel said it had carried out a wave of

attacks on Tehran, targeting what the military said were

infrastructure sites belonging to Iran's government.

It also hit targets in Lebanon, where it has resumed its war

against Iran-backed Hezbollah, killing three Lebanese

journalists in a strike on a media vehicle, Lebanon's Al Manar

TV reported, as well as a Lebanese soldier. A follow-up strike

on the rescue workers sent to assist them also caused

fatalities.

Israel's military said it had targeted one of the

journalists, accusing him of being part of a Hezbollah

intelligence unit, and saying he had reported on locations of

Israeli soldiers.

Iran kept up attacks on Israel and several Gulf states after

hitting an air base in Saudi Arabia on Friday and wounding 12

U.S. military personnel, two of them seriously, in one of the

most serious breaches of U.S. air defences so far.

Air defences shot down a drone near the residence of the

leader of the Iraqi Kurdish ruling party, Masoud Barzani, in

Erbil, security sources told Reuters early Sunday. Security

sources said on Saturday that a separate drone attack targeted

the home of the president of Iraq's Kurdistan Region.

HOUTHIS CAN STRIKE TARGETS FAR FROM YEMEN

Israel, which regularly faced missile attacks from the

Houthis before the war, confirmed a missile had been fired at it

from Yemen. There were no reports of casualties or damage.

The attack pointed to a potential new threat to global shipping,

already hit by the effective closure of the Strait of Hormuz,

the conduit for about a fifth of global oil and liquefied

natural gas supplies.

Houthi military spokesperson Yahya Saree later said the

group carried out a second attack on Israel in less than 24

hours and vowed more strikes to come.

The Houthis have shown an ability to strike targets far

beyond Yemen and disrupt shipping lanes around the Arabian

Peninsula and the Red Sea, as they did in support of Hamas in

the Gaza war.

MARKETS ALARMED BY PROSPECT OF ONGOING WAR

With U.S. midterm elections due in November, the

increasingly unpopular war has weighed on President Donald

Trump's Republican Party and he has appeared eager to end it

soon, while also threatening escalation.

Demonstrators took to city streets across the U.S. on

Saturday in anti-Trump rallies described by organizers as a call

to action against the war on Iran.

Trump has threatened to hit Iranian power stations and other

energy infrastructure if Iran does not open the Strait of

Hormuz. But he has extended a deadline he had imposed for this

week, giving Iran another 10 days to respond.

Iranian threats to attack ships in the strait have kept most

oil tankers from attempting the waterway. A few vessels have

traversed the strait without issue, including ships under the

flags of Pakistan and India, after Iranian assurances of safe

passage.

Iran has agreed to allow an additional 20 Pakistani-flagged

vessels to pass through the strait, with two ships permitted to

transit daily, Pakistan's Foreign Minister Ishaq Dar said.

Israel has targeted Iran's nuclear infrastructure, and the

head of Russia's state nuclear corporation Rosatom, which has

evacuated staff from the Bushehr nuclear power plant on the Gulf

coast, said the attacks threatened nuclear safety.

Pezeshkian said Iran would "retaliate strongly if our

infrastructure or economic centers are targeted".

Iranian attacks were reported in multiple areas across the

Gulf, including Kuwait, the United Arab Emirates and Oman.

An Iranian airstrike hit the Israeli village of Eshtaol, near

Jerusalem. Seven people were hospitalized, Israel's ambulance

service said. Aluminium Bahrain, also known as Alba,

confirmed that its facilities were targeted in an Iranian attack

on Saturday, Bahrain's state news agency reported.

In Iran, media said at least five people were killed in a

U.S.-Israeli attack on a residential unit in the northwestern

city of Zanjan, and in Tehran, the Iran University of Science

and Technology was struck.