Iran says a girls' school was hit by a deadly air strike. Here's what we know.

Mourners gathered in the Iranian city of Minab on Tuesday for the funerals of victims of what Iranian authorities say was an air strike at a school they have blamed on Israel and the U.S.

Neither the U.S. nor Israel has said it was behind the strike. An Israeli military spokesman told CBS News they had not "found any connection to our operations." Defense Secretary Pete Hegseth and Secretary of State Marco Rubio said that the Pentagon was investigating.

Iranian authorities said the explosion in Minab, in Iran's southern Hormozgan province, took place on the first day of the war on Saturday and is the largest single loss of civilian life so far reported in the conflict. Iranian health officials and state media say as many as 175 people were killed, most of them schoolgirls between the ages of 7 and 12 years old.

Journalists from international news organizations have not had unfettered access to the location to independently verify the toll or the circumstances. Iranian authorities have to give explicit approval to foreign media organizations wishing to report outside Tehran.

Here is what we know so far:

Footage of alleged incident

Footage filmed from a parking lot showed black smoke billowing from a damaged building adorned with murals featuring drawings of crayons, children and an apple.

CBS News has geolocated the clip to a building in Minab. Iranian media identified the building as the Shajareh Tayyebeh elementary school. Saturdays are regular school days in Iran.

CBS News has also confirmed the building was located in close proximity to two sites controlled by the Islamic Revolutionary Guard Corps, including the IRGC Seyyed Al-Shohada Barracks.

The Shahid Absalan clinic, under the supervision of the IRGC navy's medical command, lies 780 feet from the site, Agence France-Presse reported. 

AFP could not independently verify the date the footage from the parking lot was filmed.

Minab is strategically located close to the Strait of Hormuz, one of the world's most vital shipping lanes, especially for oil and gas.

What Iran says

Iranian state television and a local official identified the site as the Shajareh Tayyebeh girls' elementary school in Minab.

Iran has said more than 170 people were killed in what President Masoud Pezeshkian described as U.S.-Israeli strikes on the school.

Pezeshkian said on social media that "attacks on schools target a nation's future," and that a hospital was also hit.

"Targeting patients and children blatantly violates humanitarian principles," he said. "The world must condemn it. I stand with my grieving nation. Iran will not remain silent or yield to these crimes."

According to state media, Iran on Tuesday held funerals for at least 165 people including students killed in the alleged strike.

Hossein Kermanpour, a spokesman for Iran's health ministry, claimed in a post on X that dozens killed at the school were "young child martyrs."

State television carried images showing a large crowd of mourners in Minab weeping over what appear to be bodies wrapped in white shrouds. Other images released by state media on Tuesday show individuals preparing coffins draped in the Iranian flag -- some bearing photographs of children.

A third clip also shared by state media shows a large crowd gathered around similar caskets with a caption in Persian reading: "Prayer service for the children of Minab who perished."

Another aerial image showed excavators digging out at least 100 graves at an unidentified mass burial site.

AFP has been unable to independently verify the date the images were taken or access the location to verify the circumstances surrounding the events.

Pentagon investigation

When asked by BBC News on Wednesday about the alleged incident at a news briefing, Defense Secretary Pete Hegseth said the Pentagon was investigating. 

"All I can say is that we're investigating, and that we of course never target civilian targets," Hegseth said, without elaborating.  

Secretary of State Marco Rubio on Monday said that the United States would not intentionally target a school.

"The United States would not deliberately target a school. Our objectives are missiles, both the ability to manufacture them and the ability to launch them," he told reporters.

Israel "not aware" of a strike at the location

Israeli military spokesman Nadav Shoshani told CBS News that the IDF had not "found any connection to our operations," when asked about the alleged school strike. 

Asked by CBS News' Matt Gutman if he was saying the claim of a strike on the school was Iranian misinformation, Shoshani said he was suggesting "caution when using information that's provided by a regime that massacres their own people."

Shoshani also told reporters: "At this point not aware of an Israeli or an American strike there. ... We're operating in an extremely accurate manner."

"Ensure accountability"

United Nations human rights chief Volker Turk is calling for a prompt, impartial and thorough investigation into the attack.

U.N. human rights office spokeswoman Ravina Shamdasani said, "The onus is on the forces that carried out the attack to investigate it."

Norway-based rights group Hengaw said it was seeking information about the identities of the victims. In a statement, the organization said that at the time of the incident, the Shajare Tayyebeh school was holding its morning session and reportedly had about 170 students present.

The rights group said that the strike's intended targets were reportedly the nearby IRGC facilities — a claim that news outlets have not been able to independently verify.

"The establishment and expansion of military facilities in close proximity to schools and public spaces place civilians at heightened risk," Hengaw said.