DUBAI, United Arab Emirates (AP) — Iran fired on three ships in the Strait of Hormuz on Wednesday, underscoring the ongoing threat to global energy supplies and complicating efforts to bring the United States and Iran together for talks to end the war.

The attacks, which Iranian media said were carried out by Iran’s paramilitary Revolutionary Guard, came after President Donald Trump said the U.S. would indefinitely extend the ceasefire with Iran, due to expire on Wednesday.

But Trump said the U.S. would continue to blockade Iranian ports, and the attacks reinforced the dangers to traffic in the strait, through which 20% of the world’s oil and natural gas pass in peacetime.

That means that even if the ceasefire largely holds — and Iran and the U.S. do not resume major attacks — the war will continue to weigh heavily on the global economy. Already the conflict has sent gas prices skyrocketing far beyond the region and raised the cost of food and a wide array of other products. The longer the strait remains closed, the more severe and widespread the effects will be — and the longer it will take the economy to bounce back.

Iran has offered no formal acknowledgment of Trump’s extension, but an Iranian diplomat said talks would not resume until the blockade is lifted.

Three ships come under attack in the Strait of Hormuz

Iran opened fire on a container ship in the strait on Wednesday morning, and a second was attacked a short time later, according to the British military’s United Kingdom Maritime Trade Operations Center.

Iranian state television reported later reported that the ships were in the Revolutionary Guard’s custody and being taken to Iran. It identified the vessels as the MSC Francesca and the Epaminondas. The ship’s owners could not be immediately reached for comment.

The seizures represent an escalation by Iran’s leaders, who appear poised to drive a harder bargain with American negotiators after two other rounds of talks with the Trump administration ended in open warfare.

The semiofficial Nour News, Fars and Mehr news agencies then reported the Guard attacked a third vessel called the Euphoria. They said the vessel had become “stranded” on the Iranian coast, without elaborating.

The UKMTO said the first ship was attacked by a Revolutionary Guard gunboat that did not hail the ship before firing. It added that nobody was hurt in the attack.

Iran’s Nour News, however, reported that the Guard only opened fire on the ship after it had “ignored the warnings of the Iranian armed forces.” Iran’s semiofficial Fars news agency described the attack as Iran “lawfully enforcing” its control over the Strait of Hormuz.

There have been more than 30 attacks on ships in the Mideast since the war began Feb. 28 with U.S. and Israeli airstrikes on Iran.

It’s not clear when talks will restart

Iran’s ability to restrict traffic through the strait — which leads from the Persian Gulf to the open ocean — has proved a major strategic advantage.

While the ceasefire means that American and Israeli airstrikes have stopped in Iran — and Tehran’s missiles no longer target Israel and the wider Middle East — the attacks in the strait and earlier American interdictions of Iranian ships show the maritime threat remains.

Without any diplomatic agreement, those attacks may continue, likely deterring more ships from even attempting to pass through the strait, and further squeeze global energy supplies.

On Wednesday, Brent crude oil, the international standard, was trading higher than $98 a barrel, up 35% since the war started.

Iran appeared to dig in Wednesday, with its Revolutionary Guard vowing to “deliver crushing blows beyond the enemy’s imagination to its remaining assets in the region.”

The night before, hard-line supporters of Iran’s theocracy held rallies in which the Guard showed off missiles and launchers — a sign of defiance to Israel and the U.S., which devoted much of their airstrike campaign to destroying the county’s ballistic missile arsenal.

It’s not clear when talks might restart. Two Pakistani officials told The Associated Press that Islamabad is still waiting to hear from Tehran on when it will send a delegation for another round. They spoke on condition of anonymity because they were not authorized to talk to the media. Mojtaba Ferdousi Pour, the head of the Iranian mission in Egypt, told The Associated Press that no delegation would go to Pakistan until the U.S. lifts its blockade.

One killed in drone attack in Lebanon

In Lebanon, where fighting between Israel and the Iran-backed Hezbollah broke out after the U.S. and Israel launched their initial strikes, the state-run National News Agency said a morning Israeli drone strike on the village of Jabbour killed one and wounded two others.

Israel’s military denied that it had attacked the area.

A 10-day ceasefire went into effect in Lebanon on Friday, but there have been several Israeli strikes and Hezbollah claimed its first attack on Tuesday.

Since the war started, at least 3,375 people have been killed in Iran, according to authorities. More than 2,290 people has been killed in Lebanon, 23 people have died in Israel and more than a dozen have died in Gulf Arab states. Fifteen Israeli soldiers in Lebanon and 13 U.S. service members throughout the region have been killed.

SHREVEPORT (AP) — Teacher Angela Hall always starts the day gathering her preschool students in a circle in their Shreveport, Louisiana, classroom. The kids giggle. They share. And they look for who’s missing.

“Braylon, he’s not here,” she recalled one of her students saying Monday.

Braylon Snow, who just turned 5, was one of seven siblings who were fatally shot Sunday by their father in an attack that also killed their cousin. The shooting rattled classrooms in Shreveport where teachers like Hall on Monday came face-to-face with distraught parents and a messy stew of emotions.

In Hall’s classroom at Johnnie L. Cochran Head Start, it’s likely students noticed Braylon’s absence immediately. Each day, Hall instructs her students to look around for friends who aren’t there.

“When they come back tomorrow, we can tell them, ‘Hey, we missed you, we’re glad you’re back’” she tells them.

But Hall wasn’t ready to tell the students that the boy she described as a “cool little dude” wasn’t returning. She kept circle-time moving. Numb and heartbroken, she lasted until noon and then went home.

“I’m no good to my babies right now because I just feel like I need to be in a moment of silence and just pray,” she said.

Preschool comes to an end

At Head Start, preparation’s for next month’s graduation ceremony have been in full swing. Hall, an organist and pianist at her local Baptist church, wrote a song for the ceremony.

Students, who dress in caps and gowns for the festivities, have been busy learning the words, excited about the prospect of starting kindergarten in the fall. Hall was working hard to make sure they were ready.

Just last Thursday, she pulled Braylon’s mother aside during morning drop-off, boasting that Braylon was writing his first and last name. Braylon also was getting so independent, squirting syrup for his pancakes onto his plate by himself. He didn’t even need a reminder to wash his hands.

“Braylon doesn’t give me any problems,” she told his mother.

Braylon greeted Hall — known to her students as “Mrs. Hall” — each day with a small wave.

As the year progressed, she nudged more gap-toothed smiles from him. He loved his time on the playground — playing chase, tag and even partaking in “a little wrassling.” She laughed as she remembered it.

“He was for the majority of the time kind of a quiet little soul in the classroom,” she said. “When he did get a little extra energy or something, it was just a joy to see him smile and laugh.”

News of the shooting emerges

But then came Sunday. After church, she went to her mother’s house. It was then that she stumbled across an article about the shooting.

The number of victims was so high she struggled to comprehend it. Then she learned Braylon was among the victims. She also knew one of his brothers. He had been a Head Start student at the school last year.

“I just broke down and just started crying,” she said.

The same thing happened Monday morning at drop off when she locked eyes with a parent. Neither could say anything; the preschoolers were all around them.

“I just immediately broke down,” she said. So too did the parent and a teacher’s aide.

She is relying on her faith now. She prays for the dead, for the families and also for the teachers.

“And I’m just praying for all the educators that were connected to these children because it’s tough because my parents’ babies, they become my babies. And I treat them like they’re my own. So I’m just really praying that he sustains us all during this time.

“Just give us that strength.”