GENEVA, Switzerland: A UN investigation has accused U.S. forces of carrying out two strikes in Iran that it said amounted to war crimes, while also finding that Iranian authorities committed crimes against humanity during a deadly crackdown on anti-government protests.

The Independent International Fact-Finding Mission on Iran said on September 17 that there were reasonable grounds to believe the U.S. was responsible for strikes on a school and a sports facility in February. The report also examined the Iranian government's response to nationwide protests that began in late December.

The Iranian and U.S. permanent missions in Geneva did not immediately respond to Reuters requests for comment.

U.S. officials have previously said that military operations are conducted in accordance with the law of armed conflict. Iran has consistently rejected allegations of systematic rights violations.

The UN experts said they found reasonable grounds to believe that U.S. forces were responsible for an attack on Shajareh Tayyebeh Primary School in the city of Minab. Iranian officials said more than 150 people were killed, including about 120 schoolchildren.

The mission concluded that the attack was indiscriminate, caused civilian deaths and damaged civilian infrastructure, making it a war crime under international law.

According to the report, the U.S. relied on intelligence suggesting that a senior Iranian military commander was at the site but did not properly verify the information before launching the strike.

Investigators said the failure to update targeting intelligence and confirm that the building was a military target went beyond simple negligence.

"Rather, the U.S. directed the strikes at the building of the school while being aware of a substantial risk of striking a civilian object and acting recklessly as regards the possibility that this would happen."

In June, U.S. President Donald Trump said that "nobody" had deliberately attacked a girls' school in Iran in February, citing an investigation into the incident. Reuters had earlier reported that an initial internal U.S. military investigation showed that U.S. forces were likely responsible for the deadly strike in Minab in southern Iran.

The Pentagon has since expanded the investigation but has not published any preliminary findings.

UN experts said the school was clearly identifiable as a civilian building and found no evidence that it was being used for military purposes.

The experts reached a similar conclusion about a strike on a sports center in Lamerd. The report said the attack damaged nearby residential buildings and a school and killed or injured 22 civilians. It concluded that the strike was indiscriminate and therefore constituted a war crime.

U.S. Central Command said in a March statement that U.S. forces did not carry out any strikes on the city of Lamerd that day.

Iran Attacked Civilians

The UN mission found that Iranian authorities carried out a widespread and systematic attack against civilians during protests that began in late December last year. The alleged abuses included unlawful killings, torture, arbitrary detention, enforced disappearances and severe restrictions on freedom of expression.

Rights groups said bystanders were among those killed during the biggest crackdown since Shi'ite Muslim clerics took power in the 1979 revolution. Tehran blamed "terrorists and rioters" supported by opponents living abroad and foreign enemies, including the U.S. and Israel.

The mission said it could not independently verify the death toll but believed the number of people killed and injured was likely much higher than official figures. Those figures said 3,038 people were killed and 25,000 were injured.

The report said the government's response to the protests, including violence and killings, cutting off the internet, and using the death penalty, marked a significant escalation from previous methods of suppressing dissent.