* No US attacks on Iran for first time in two weeks

* Iran accuses Ukraine of striking commercial ship in

Caspian Sea

* Reports of damage to Saudi oil depot as air defences

intercept missiles from Yemen

* Houthis' entry into conflict threatens to reignite Yemen's

civil war

By Raphael Satter and Lefteris Papadimas

WASHINGTON, July 26 (Reuters) - Signs of the Iran war's

spread emerged this weekend despite a pause in U.S. strikes, as

Yemen's Iran-aligned Houthis attacked Saudi oil installations

along the Red Sea coast and Iran accused Ukraine of targeting an

Iranian vessel in the Caspian Sea.

The U.S. military said on Saturday that its naval blockade

against Iran "remains in full effect" but did not explain why it

halted a streak of 13 nights of escalating strikes. Asked about

the pause, a senior official in President Donald Trump's

administration said Trump "has always been clear that his

preference is diplomacy, but he has shown Iran what will happen

if they fail to come to the table in a serious way."

There were also no reports on Saturday of attacks from Iran

on neighboring countries, like those that have been taking place

daily in response to the U.S. attacks.

Despite the lull in the Gulf, fighting between Iran's Houthi

allies and Saudi Arabia on Saturday indicated the war, which has

already disrupted energy supplies through the Strait of Hormuz,

could affect a second major shipping route and reignite Yemen's

civil war.

Separately, Iran's Foreign Ministry accused Ukraine of attacking

an Iranian commercial vessel in the ​Caspian Sea, saying it

resulted in an explosion that killed ‌a sailor and injured

another.

Earlier on Saturday, Ukrainian President Volodymyr Zelenskiy

in a social media post praised the results of "long-range

strikes" in the Caspian Sea, alluding to vessels shipping

military cargo, but did not identify the nationality of the

targets.

WAR THREATENS TO SPREAD TO YEMEN

Houthi military spokesperson Yahya Saree said the group

struck sites belonging to Saudi state oil company Aramco in

Jizan and Yanbu. Video shared on social media and verified by

Reuters showed a large column of smoke rising from the direction

of the Aramco refinery in Jizan.

Two Asia-based trading sources said they had been informed

of potential damage to fuel and oil storage sites at Jizan.

Aramco did not respond to requests for comment.

In Yanbu, two ballistic missiles aimed at oil installations

were intercepted by a U.S.-made Patriot battery operated in

Saudi Arabia by the Greek military under an agreement with

Riyadh, Greek security sources said.

Yanbu, Saudi Arabia's main Red Sea oil port, has become a

key route for Saudi oil skirting the Strait of Hormuz, which

Iran has blockaded. Up to 400,000 barrels can be processed daily

at the oil refinery in Jizan, a city on the Red Sea close to the

Yemeni border.

In Yemen, the air force of the Saudi-backed, internationally

recognized government, which has opposed the Houthis for more

than a decade, struck Houthi launch sites and arms depots in the

Marib and al-Jawf provinces, Yemeni officials said.

Earlier, the Saudi-led military alliance said it bombed

Houthi military positions on Friday in the Red Sea port of

Hodeidah.

The Yemeni officials said both sides in Yemen's civil war

were mobilizing forces along the front.

SAUDI-LED COALITION STRIKES HODEIDAH

Saudi Arabia has led an Arab coalition battling the Houthis

for more than a decade since the Iran-aligned fighters captured

Yemen's capital, Sanaa.

The Yemeni civil war, during which hundreds of thousands of

people died from fighting and famine, has been paused under a

ceasefire since 2022. But that truce broke down this month, with

the Houthis effectively joining the wider war their Iranian

allies have waged since being attacked by the U.S. and Israel.

The Houthis have declared a naval blockade of Saudi Arabia

over the past week, and Houthi leader Abdul Malik al-Houthi said

all Saudi oil facilities could be targets. On Thursday, the

Houthis struck two Saudi tankers in the Red Sea.

American forces recently resumed their own blockade on Iranian

ports. U.S. Central Command, whose coverage area includes the

Middle East, said it disabled a ship whose crew attempted to run

the blockade despite "repeated warnings" on Friday in the Gulf

of Oman.

An interim truce effectively collapsed two weeks ago, with

U.S. forces striking targets in southern Iran in response to

Iranian disruption of shipping in the Strait of Hormuz.

On Friday, Trump said the ‌U.S. and Iran were in talks to

​negotiate an end ​to their conflict, but ⁠repeated that Tehran

​was not yet ready ​for a deal.