The United States was responsible for a Tomahawk missile strike on an Iranian elementary school due to a "targeting error", The New York Times reported on Wednesday.
The newspaper, citing US officials, said the investigation into the February 28 attack was ongoing, but preliminary findings were that the United States was responsible.
The US military was conducting strikes on an adjacent Iranian base of which the school building was formerly a part and target coordinates were set using outdated data, it said.
President Donald Trump suggested earlier this week that Iran itself may have been responsible but later said he could "live with" whatever the investigation reveals.
Asked by reporters about the Times report on Wednesday, Trump said: "I don´t know about it."
Iran has said the strike on the elementary school in the southern city of Minab killed more than 150 people.
The Times said US Central Command officers created the target coordinates for the strike using outdated data provided by the Defence Intelligence Agency.
It said investigators were still looking at why outdated information was used in planning the strike and who failed to verify the data.
The newspaper said the school is on the same block as buildings used by the Islamic Revolutionary Guard's navy and the site of the school was originally part of the base.
It said the building housing the school had been fenced off from the base between 2013 and 2016.
AFP has been unable to access the location of the strike to independently verify the circumstances around it or the toll reported by Iranian media.
President Masoud Pezeshkian blamed the United States and Israel for the strike.
Israel has consistently denied any involvement in or knowledge of the strike and US Secretary of State Marco Rubio said last that the United States would not intentionally target a school.
