Iran has freedom of expression, but the protests happening now are unacceptable "acts of chaos", Iran's President Ebrahim Raisi said on Thursday, adding that he had ordered a probe into the death of a young woman that sparked bloody demonstrations, News.az reports.

"Rights issues must be considered all around the world with a single standard," Raisi told a news conference on the sidelines of the United Nations General Assembly.

"There is freedom of expression in Iran ... but acts of chaos are unacceptable."