The United Nations rights chief has stressed the need for “impartial investigations” into a strike on a school in Iran, urging the US to move “very quickly” with its announced probe, AFP reports.

UN rights chief Volker Turk condemned “this absolutely tragic incident”.

“What we have asked for is obviously prompt, transparent and impartial investigations, which we understand has been announced by the United States,” he told reporters in Geneva.

“We need this to happen very quickly, and we need to also make sure that there is accountability as well as redress for the victims,” he insisted.

Turk, who said he hoped to go to Washington later this month, said there were “significant concerns about the respect for international humanitarian law, especially the conduct of hostilities… (and what) measures of precaution, of distinction, of proportionality are taken”.

When it comes to a school, he said, that was “clearly a civilian institution that should never be attacked”.