Intense air strikes have pounded Tehran and other Iranian cities on the seventh day of the US-Israeli war on the country, amid warnings from the United States Defence Secretary Pete Hegseth that the bombardment was “about to surge dramatically.”

Israel’s military said Friday morning it had begun a new “broad-scale wave of strikes” on Tehran, while the US said its B-2 bombers had dropped dozens of “penetrator” bombs on deeply buried ballistic missile launchers inside the country.

Massive explosions hit several locations in the Iranian capital, Tehran, overnight, including residential areas and the vicinity of Tehran University, according to news reports and an Al Jazeera team on the ground.

An Iranian military academy was also struck, while a journalist from Iran’s state broadcaster was reporting live near the site.

Reporting from Tehran, Al Jazeera’s Tohid Asadi said the bombardment in the capital had been more intense than previously seen, with many strikes in the east and southeast of Tehran.

“From the very early hours of today and into the morning we have been witnessing a continued wave of massive strikes,” he said, adding the shockwaves of the blast could be felt in the bureau of Al Jazeera.

“I can say that compared to previous days, we saw heavier bombardment overnight, at least in the capital,” he said, reporting massive explosions and fighter jets in the skies, and a huge column of thick smoke rising from an air strike.

Buried missile launchers bombed: US

Explosions were also reported around the Iranian city of Kermanshah, in an area home to multiple missile bases, as well as in Shiraz and Isfahan.

The Israeli military said strikes have already destroyed most of Iran’s air defences and missile launchers.

Admiral Brad Cooper, head of US Central Command (CENTCOM) said that early Friday, US B-2 stealth bombers dropped dozens of 2,000 pound “penetrator” bombs on deeply buried ballistic missile launchers inside Iran.

“We’ve also struck Iran’s equivalent of Space Command, which degrades their ability to threaten Americans,” Cooper said.

Speaking alongside Cooper, Hegseth described an upcoming surge in the bombardment.

“It’s more fighter squadrons, it’s more capabilities, it’s more defensive capabilities,” Hegseth said. “And it’s more bomber pulses more frequently.”

US ‘likely responsible’ for school attack: Report

At least 1,230 people have been killed in the strikes on Iran since Saturday, Iranian state media has reported. UNICEF said on Friday that at least 181 children were among the dead in Iran.

Among the young victims were at least 175 children killed when a girls’ school in Minab, in southern Iran, was hit on the first day of the US and Israeli strikes on Iran, according to the IRGC.

Amid scrutiny over the incident, Hegseth on Wednesday acknowledged the US military was investigating the incident.

Reuters reported, citing two US officials, that US military investigators believed it was likely that US forces were responsible for the apparent strike, but have not yet reached a final conclusion.

Deliberately attacking a school would be a war crime, and if a US role were to be confirmed, the strike would rank among the worst cases of civilian casualties in decades of US wars in the Middle East.

Qatar’s Energy Minister Saad al-Kaabi has said exports from the Gulf region could come to a halt “within weeks” if the war on Iran continues to escalate, throwing global energy markets into turmoil.

Al-Kaabi told The Financial Times (FT) newspaper in an interview published on Friday that if the war continues for weeks, “GDP growth around the world will be impacted”.

“Everybody’s energy price is going to go higher. There will be shortages of some products and there will be a chain reaction of factories that cannot supply,” al-Kaabi was quoted as saying.

Qatar on Monday halted liquefied natural gas (LNG) production as Iran fired a barrage of missiles and drones at the country and its Gulf neighbours in response to attacks by the United States and Israel, which began on Saturday.

The Iranian attacks have increasingly targeted energy infrastructure, driving a jump in gas prices and raising alarm around the world.

Qatar’s LNG production is equivalent to about 20 percent of global supply and plays a key role in balancing Asian and European markets’ demand for the product.

“Everybody that has not called for force majeure we expect will do so in the next few days that this continues,” al-Kaabi told the FT, referring to a provision that frees companies from liability or obligations in the case of extraordinary events.

“All exporters in the Gulf region will have to call force majeure,” he said.

The minister also said that, even if the war ended immediately, it would take Qatar “weeks to months” to return to a normal cycle of deliveries.

Thijs Van de Graaf, an energy fellow at the Brussels Institute for Geopolitics, explained that tanker traffic through the Strait of Hormuz, a strategic Gulf waterway, has dropped dramatically due to the war.

“All of the producers in the Gulf who rely on that export route will have to shut in production, like Iraq has already done for two or three major oil fields,” Van de Graaf told Al Jazeera.

“And this could have long-term, knock-on effects, because you do not turn on and off an oil well like flipping the switch of a light,” he said. “This is bad news and the clock is ticking for many producers in the region.”

No end in sight

The war has shown no sign of abating, with senior US officials promising to rain “death and destruction” on Iran amid growing concerns of a possible ground invasion.

Meanwhile, Iran has continued to fire at targets across the region despite international condemnation of the strikes as a violation of international law.

In a social media post on Friday, Iranian President Masoud Pezeshkian said Iran was “committed to lasting peace in the region yet we have no hesitation in defending our nation’s dignity & sovereignty”.

Addressing a renewed push for mediation, Pezeshkian said any such efforts “should address those who underestimated the Iranian people and ignited this conflict”, referring to the US and Israel.