DUBAI, United Arab Emirates (AP) — U.S. airstrikes targeting an oil port held by Yemen’s Houthi rebels killed 74 people and wounded 171 others, the group said Friday, marking the single-deadliest known attack under President Donald Trump’s new campaign targeting the rebels.

Assessing the toll of Trump’s campaign, which began March 15, has been incredibly difficult as the U.S. military’s Central Command so far has not released any information on the campaign, its specific targets and how many people have been killed. Meanwhile, Yemen’s Houthi rebels strictly control access to areas attacked and don’t publish complete information on the strikes, many of which likely have targeted military and security sites.

But the strike on the Ras Isa port, which sent massive fireballs shooting into the night sky, represented a major escalation for the American campaign by hitting oil facilities for the first time.

In a statement, Central Command said that “U.S. forces took action to eliminate this source of fuel for the Iran-backed Houthi terrorists and deprive them of illegal revenue that has funded Houthi efforts to terrorize the entire region for over 10 years.”

“This strike was not intended to harm the people of Yemen, who rightly want to throw off the yoke of Houthi subjugation and live peacefully,” it added. It did not acknowledge any casualties from the attack or offer any damage assessment.

Satellite images from Planet Labs PBC and analyzed by The Associated Press Friday showed destroyed tanks and vehicles at the port as oil leaks into the Red Sea.

The Iranian-backed Houthis later Friday launched a missile toward Israel that was intercepted, the Israeli military said. Sirens sounded in Tel Aviv and other areas.

The war in Yemen, meanwhile, further internationalized as the U.S. alleged a Chinese satellite company was “directly supporting” Houthi attacks, something Beijing declined to directly comment on Friday. And a second round of negotiations between Iran and the U.S. over Tehran’s rapidly advancing nuclear program, which America has linked to the Yemen campaign, is due to happen Saturday in Rome.

US strikes spark massive fireball

The Ras Isa port, a collection of oil tanks and refining equipment, sits in Yemen’s Hodeida governorate along the Red Sea. It is just off Kamaran Island, targeted by intense U.S. airstrikes over the past few days.

The Houthis’ al-Masirah satellite news channel aired graphic footage of the aftermath, showing corpses strewn across the site and smashed tanker trucks ablaze.

The port also is the terminus of an oil pipeline stretching to Yemen’s energy-rich Marib governorate, which remains held by allies of Yemen’s exiled government. The Houthis expelled that government from Yemen’s capital, Sanaa, back in 2014. However, oil exports have been halted by the decadelong war and the Houthis have used Ras Isa to bring in oil.

Ras Isa takes in gasoline, diesel and liquefied petroleum gas for the Houthis. The damage from the strikes could have serious impacts on life in Houthi-held areas of Yemen.

The Houthis denounced the U.S. attack as a “completely unjustified aggression.”

“It targets a vital civilian facility that has served the Yemeni people for decades,” the Houthis said in a statement.

On April 9, the U.S. State Department issued a warning about oil shipments to Yemen, saying it would “not tolerate any country or commercial entity providing support to foreign terrorist organizations, such as the Houthis.”

The attack follows Israeli airstrikes on the Houthis which previously hit port and oil infrastructure used by the rebels after their attacks on Israel, including Ras Isa.

Oil depot attack deadliest so far known in Trump’s Yemen campaign

The attack represented the deadliest known attack so far in the campaign, analysts said. However, “it’s been so difficult to assess the fatalities,” said Luca Nevola, the senior analyst for Yemen and the Gulf at the Armed Conflict Location & Event Data Project.

“Since they are targeting civilian areas, there’s a lot more victims but it’s also difficult to assess how many because the Houthis are releasing these umbrella statements that cover all the victims … or tend to stress only the civilian victims,” Nevola said.

Further complicating the situation is the U.S. strikes hitting military targets, said Mohammed al-Basha, a Yemen expert at the Basha Report risk advisory firm. He pointed to an American attack that Trump highlighted online with black-and-white strike footage, that may have killed some 70 fighters.

“Although the Houthis claimed it was a tribal gathering, they neither released any footage nor named a single casualty, strongly suggesting the victims were not civilians but affiliated fighters,” al-Basha said. “However, the overnight strike on the Ras Isa Fuel Port marks the first mass-casualty incident the Houthis have openly acknowledged and publicized.”

Chinese satellite firm accused by US of aiding Houthi attacks

Meanwhile, State Department spokesperson Tammy Bruce in a briefing with journalists accused Chang Guang Satellite Technology Co. Ltd., a commercial satellite image provider, of “directly supporting Iran-backed Houthi terrorist attacks on U.S. interests.”

Bruce did not elaborate in detail, but acknowledged a report by The Financial Times that quoted anonymous American officials saying the firm linked to the People’s Liberation Army has provided images allowing the rebels to target U.S. warships and commercial vessels traveling through the Red Sea corridor.

Bruce said “Beijing’s support … of the satellite company” “contradicts their claims of being peace supporters.”

Chinese Foreign Ministry spokesperson Lin Jian, responding to a question about the allegation, said Friday: “I am not familiar with the situation you mentioned.” However, he insisted China is seen as urging countries “to make more efforts conducive to regional peace and stability.”

“Since the escalations in the Red Sea situation, China has been playing a positive role in de-escalating the situation,” Lin said. “Who is promoting talks for peace and de-escalating the tensions, and who is imposing sanctions and pressure?”

Chang Guang did not respond to request for comment. The U.S. Treasury sanctioned the company in 2023 for allegedly providing satellite images to the Russian mercenary force the Wagner Group as it fought in Ukraine.

It remains unclear whether Chang Guang is linked to the Chinese government. The U.S. government in the past has used images taken by American commercial satellite companies to share with allies, like Ukraine, to avoid releasing its own top-secret pictures.

US strikes are part of monthlong intense campaign

An AP review has found the new U.S. operation against the Houthis under President Donald Trump appears more extensive than that under former President Joe Biden. The new campaign of airstrikes started after the rebels threatened to begin targeting “Israeli” ships again over Israel blocking aid entering the Gaza Strip.

The Houthis targeted more than 100 merchant vessels with missiles and drones, sinking two of them and killing four sailors from November 2023 until January of this year. That has greatly reduced the flow of trade through the Red Sea corridor, which typically sees $1 trillion of goods move through it. The Houthis also launched attacks targeting American warships without success.

This story was originally featured on Fortune.com