* Iran strikes hit Qatar gas facilities, target Riyadh

* Oil price jumps about 7%

* Trump says US not told in advance of Israel's gas field

strike

* Trump warns Iran not to attack Qatar again

* Trump considering sending more troops to Middle East

By Andrew Mills and Timour Azhari

DOHA/RIYADH, March 19 (Reuters) - European countries

scrambled to cushion the impact of soaring oil prices on

Thursday after tit-for-tat strikes on Gulf energy plants,

including the world's largest gas plant in Qatar - the most

economically significant escalation of the U.S.-Israeli war on

Iran.

State oil giant QatarEnergy reported "extensive damage"

after Iranian missiles hit the Ras Laffan Industrial City, which

processes about a fifth of the world's liquefied natural gas, in

response to Israel's bombing of Iran's major gas field. Saudi

Arabia's back-up oil port on the Red Sea was also attacked.

The seemingly precise strikes were a dramatic demonstration

of Iran's continuing ability to exact a heavy price for the

U.S.-Israeli campaign and the limits of air defences to protect

one of the Gulf region's most valuable and strategic assets.

They also suggested a lack of coordination of strategy and

war aims between the two main aggressors almost three weeks into

the war.

INTEREST RATES AND ENERGY PRICES WORRY EUROPE

As surging energy prices stoked inflation fears, the

likelihood of interest rate hikes increased ahead of Thursday's

European Central Bank and Bank of England meetings.

And European Union leaders were also set to try to offset

the jump in energy costs at a summit in Brussels, with few easy

options available.

Brent futures were up about 7% to more than $114 a

barrel by 1026 GMT. Meanwhile European gas prices have leapt by

over 60% since the war began on February 28.

Japanese and South Korean stocks fell around 3% while the

pan-European index was down 2%.

Iranian aerial attacks since Wednesday have also forced the

UAE to shut its Habshan gas facility and set off fires at

Kuwait's Mina Al Ahmadi and Abdullah Port oil refineries.

Perhaps just as significantly, Saudi Arabia intercepted a

ballistic missile launched towards Yanbu, the port city that

serves as the kingdom's only outlet for crude exports since Iran

in effect closed the Strait of Hormuz, through which around a

fifth of the world's crude oil and liquefied natural gas

normally passes.

A drone also fell on the Aramco-Exxon refinery, SAMREF, in

Yanbu, the Saudi defence ministry said, adding that damage was

being assessed.

Saudi Arabia said it had intercepted and destroyed four

ballistic missiles launched toward the capital Riyadh on

Wednesday as well as an attempted drone attack on a gas facility

in the country's east.

Iran's armed forces command said strikes on Iran's energy

infrastructure had led to "a new stage in the war" in which it

had attacked energy facilities linked to the United States.

"If strikes (on Iran's energy facilities) happen again,

further attacks on your energy infrastructure and that of your

allies will not stop until it is completely destroyed,"

spokesman Ebrahim Zolfaqari said, according to state media.

TRUMP SAYS ISRAEL ACTED ALONE IN ATTACKING GAS FIELD

Trump said the United States had had no advance knowledge of

Israel's attack on Iran's gas field and that Qatar - a close

partner of Washington and host to the Gulf's biggest U.S.

airbase - had not been involved.

"Israel, out of anger for what has taken place in the Middle

East, has violently lashed out at a major facility known as

South Pars Gas Field in Iran," Trump posted on X.

"Unfortunately, Iran did not know this, or any of the

pertinent facts pertaining to the South Pars attack, and

unjustifiably and unfairly attacked a portion of Qatar's LNG Gas

facility."

The Wall Street Journal, however, reported that Trump had

supported Israel's plan to attack South Pars, and Israeli media

reported widely on Wednesday that it had been carried out with

Trump's consent and in coordination with Washington.

A source briefed on the Israeli campaign said Trump's

remarks were surprising given that Israel was closely

coordinating its campaign with the U.S.

Israel has been hoping sustained military pressure on Iran,

including the assassinations of senior figures, would weaken the

government enough to trigger a popular uprising.

However, Israeli officials have publicly acknowledged that

such an outcome is far from certain, and there has been little

sign that the Tehran government is losing its grip.

In his post, Trump said that if Iran attacked Qatar again,

"the United States of America, with or without the help or

consent of Israel, will massively blow up the entirety of the

South Pars Gas Field at an amount of strength and power that

Iran has never seen or witnessed before".

South Pars is the Iranian sector of the world's largest

natural gas deposit, shared with Qatar.

Since the start of the conflict, Tehran has targeted not

only Israel, but also U.S. diplomatic and military facilities

across the Gulf, while warning neighbouring states against

hosting attacks on Iran.

SOURCES SAY TRUMP CONSIDERS SENDING MORE TROOPS

A U.S. official and three other people familiar with the

planning told Reuters that Trump, politically vulnerable to

rising fuel prices among his core voters, was considering

sending thousands more U.S. troops to the Middle East.

Those troops could be used to restore the safe passage of

oil tankers through the Strait of Hormuz, where Iran has been

selectively attacking vessels.

Trump this week asked U.S. allies to help reopen the strait,

but his request has so far been rebuffed.

More than 3,000 people have been killed in Iran since the

U.S.-Israeli attacks began, the U.S.-based Iran human rights

group HRANA estimates, with millions forced to leave their

homes.

Authorities in Lebanon say 900 have been killed there and

800,000 displaced. Iranian attacks have killed people in Iraq

and across the Gulf states, and at least 13 U.S. service members

have died.