Khaman Maluach and his teammates on the Duke Blue Devils lost against the University of Houston on Saturday night in a semifinal of the NCAA men’s basketball tournament. Now, he may be facing a new opponent off the court: the U.S. government.

The immigration status of Maluach, a star freshman center from South Sudan, appeared to be in question Sunday, one day after Secretary of State Marco Rubio revoked the visas of all South Sudanese passport holders living in the United States. He said the measure was effective immediately.

In a social media post, Rubio said the move was “due to the failure of South Sudan’s transitional government to accept the return of its repatriated citizens in a timely manner.”

Maluach, who grew up as a refugee in Uganda and played on South Sudan’s basketball team at the Paris Olympics, is widely seen as a first-round pick in this year’s NBA draft if he chooses to turn professional.

He left after the game Saturday night without addressing the media, and he could not be immediately reached for comment Sunday. But Frank Tramble, a spokesperson for Duke, said in a statement that the university was aware of Rubio’s announcement. “We are looking into the situation and working expeditiously to understand any implications for Duke students,” he said.

Last week, several schools including Harvard University, Ohio State, the University of Colorado and North Carolina State have made statements saying that the visas of some of their international students had been revoked. The moves come as the Trump administration continues its overall crackdown on immigration. Last month, Rubio said he revoked the visas of more than 300 students, visitors and others.

Many of them have been swept up by the government as part of what the Trump administration says is a campaign against antisemitic activists on campus. Those include Mahmoud Khalil, a graduate of Columbia University and a leader of pro-Palestinian demonstrations on the university’s campus, and Rumeysa Ozturk, a Tufts University student from Turkey, who co-wrote an opinion essay critical of Israel’s conduct of the war in the Gaza Strip published in the student newspaper. Both are legal U.S. residents but are currently held in custody by the government, which seeks to deport them. Khalil and Ozturk are fighting the actions in court.

This article originally appeared in The New York Times.

CAIRO — It was still dark out when a group of ambulances and a fire truck dispatched by Palestinian emergency response services slowed to a halt in Rafah, the southernmost city in the Gaza Strip, early on March 23. They had been sent to find their paramedic colleagues, who had headed out in an ambulance on a rescue mission earlier that morning before disappearing.

The convoy stopped next to the missing ambulance, which stood by the side of the road near some United Nations warehouses. When paramedics got out to look, Israeli soldiers about 50 meters away opened fire on them, according to two men who said they had witnessed the shootings.

The two men saw what happened, they said, because they were being held by the same Israeli troops.

One of the two, Munther Abed, 27, a volunteer paramedic, said he had been detained after surviving an earlier attack on the missing ambulance that killed two other crew members. The other man, Dr. Saeed al-Bardawil, 55, a physician, said he had been detained alongside Abed when he and his son were stopped by Israeli troops on their way to go fishing about 4:45 a.m.

The New York Times interviewed the two men separately in Gaza days after the United Nations said it had found the bodies of 15 rescue workers — eight from the Palestine Red Crescent Society, six from Gaza’s Civil Defense and one from the United Nations — in a mass grave. Their ambulances, their fire truck and a U.N. vehicle, which had been crushed, were half-buried nearby. The United Nations has accused Israel of killing the 15 workers, discarding their bodies and destroying the vehicles.

The two men’s accounts appear to support those accusations. Although their stories could not be independently confirmed, details they gave also matched the sequence of events in a video obtained and verified by the Times, discovered on the cellphone of one of the dead paramedics. That video shows an intense barrage of gunfire hitting the convoy just as dawn breaks.

“I wasn’t blindfolded — I saw everything clearly,” al-Bardawil said. “The medics got out to inspect the damaged ambulance. That’s when the soldiers opened heavy fire.”

The video and the witnesses’ accounts contradict the Israeli military’s initial explanation for the attack, which was that its forces had opened fire on the emergency vehicles because they were “advancing suspiciously” without headlights or emergency signals. The video shows that the ambulances and fire truck were clearly marked and flashing their emergency lights. Abed and al-Bardawil also said the vehicles’ headlights and emergency signals had been on and that they had stopped when the shooting began.

The killings have drawn international condemnation and scrutiny. On Saturday, an Israeli military official told reporters that the military’s initial version of events had been partly “mistaken.” The military said in a statement Sunday that the episode was “under thorough examination.”

Speaking anonymously under Israeli military rules, the military official said Israeli officials believed that at least six of the 15 dead had been Hamas operatives, but did not provide any evidence. The official declined to comment on whether any of those killed had been armed.

Abed said he had been a volunteer with Red Crescent in Gaza since 2015, working in his hometown, Rafah. He also owns a bookshop, he said. Red Crescent jobs have been something of a family tradition: his father is a Red Crescent manager; his brother Mohammed, 25, also worked for the humanitarian agency until he was killed in a drone strike in May 2024.

In the predawn hours the day of the attack, Abed recalled, his ambulance crew was dispatched to help evacuate civilians after an Israeli attack in Rafah.

As they drew nearer, Abed suddenly heard a barrage of shots hitting the ambulance, he said. Everything died instantly: the interior lights, the siren, the engine. Then he heard a sound he knew from experience — a death rattle, he called it — coming from his two colleagues in the front. One was a fellow paramedic, Ezzedine Shaath, and the other was the driver, Mostafa Khafaja.

Outside the ambulance, he could hear people speaking Hebrew, he said. Certain he was about to die, Abed began reciting the Shahada, a Muslim declaration of faith.

Then Israeli soldiers opened the door, and someone ordered him to strip naked and kneel, Abed said. The soldiers began hitting him on the back with the butts of their rifles, he said. They spit on him, cursed him and questioned him, he said, asking where he was on Oct. 7, 2023, the date of the Hamas-led attack on Israel that ignited the war.

(BEGIN OPTIONAL TRIM.)

“You’re a terrorist — why are you here?” one soldier shouted, Abed recalled.

Abed said they pushed him backward and pressed a rifle into his neck so hard he thought he might suffocate. One soldier held a knife just next to his wrist, he said.

The Israeli military official said soldiers had killed two Hamas operatives and detained a third from the initial ambulance. He did not explain why, if Abed was an operative, he was later released.

(END OPTIONAL TRIM.)

Shortly after Abed was detained, two new people joined him in handcuffs: Al-Bardawil, a general practitioner, and his 12-year-old son, Mohammed, who were stopped by soldiers as they headed to the beach to fish, which al-Bardawil loved to do.

Whenever a car approached, al-Bardawil recalled, the Israeli soldiers lay flat on the ground and ordered the detainees to follow suit. The soldiers did not fire at any of those vehicles, he said.

Soon after the al-Bardawils were detained, the elder al-Bardawil and Abed said, the men saw emergency vehicles approaching. Abed recognized a fire truck and an ambulance from Gaza’s Civil Defense.

An Israeli officer was talking to soldiers in Hebrew nearby, Abed said, and as soon as he finished speaking, the soldiers opened fire on the vehicles. The shooting lasted for several minutes, he said.

As more red emergency lights approached, Abed was told to move to a place where his view was blocked — and then heard more gunfire, he said. Al-Bardawil, who described still having a direct sightline, said the Israelis had been firing at oncoming ambulances.

As the sun rose, about 20 Israeli tanks and about 100 Israeli soldiers arrived on the scene, Abed said, and dug four large holes in the ground. Satellite images from this time obtained by the Times showed the four ambulances and Civil Defense truck clumped together toward the side of the road, next to where they were later buried. Three bulldozers, an excavator and Israeli tanks were nearby.

When it was fully light, he said, he saw an Israeli bulldozer, which he identified as a Caterpillar D9, crushing five ambulances and the fire truck and pushing them into one of the holes. He also saw a crumpled U.N. vehicle, he said. Al-Bardawil said he witnessed the bulldozer plowing the bodies into the ground along with the vehicles.

The Israeli military officer said the soldiers had buried the bodies to protect them from wild animals and that they had used heavy equipment to push the vehicles to clear the road.

Abed said he was relieved when the Israelis brought another Red Crescent paramedic, Asaad al-Nasasra, still alive, over to the group of detainees. In handcuffs and a blindfold, al-Nasasra, whispered to him what he knew about their colleagues, Abed recalled.

Two looked wounded, one of them seriously, he said al-Nasasra told him. And last he had seen them, al-Nasasra recalled, two others were reciting the Shahada.

One Israeli soldier sounded triumphant when Abed asked about the other ambulance workers, he recalled. “Your colleagues — all of them are gone!” he told him, mockingly, in broken Arabic, the paramedic said.

“May God have mercy on their souls,” Abed recalled replying.

Another soldier told him, also in broken Arabic, that God had taken “those terrorists” to hell.

Eventually, the soldiers led al-Nasasra, the other paramedic, away. He is still missing, according to the Red Crescent.

That afternoon, al-Bardawil and Abed said they were asked to help the soldiers by telling a large group of civilians who had gathered to evacuate the area. After they did so, they were released, they said.

(STORY CAN END HERE. OPTIONAL MATERIAL FOLLOWS.)

Hurrying away, Abed left his jacket, ID card and bank card behind.

His parents had been panicking since they heard about the attacks.

“Reassure me you’re OK, dear son,” his mother, Somaya Abed, 49, had texted him at 7:52 a.m. that day, according to a message she showed a Times reporter.

There was no reply until Abed was released around 4 p.m. He called his father right away.

“I’m finally out and safe,” the younger Abed said.

But after hours of repeated beatings, he could barely walk, he said. A Red Crescent vehicle had to bring him home.

This article originally appeared in The New York Times.