The New York Times reported that new video footage recorded by a security camera showed that two Iranian missiles hit the Ukrainian commercial plane, the first 30 seconds to the second, after taking off from Tehran on January 8.
The newspaper said that the two missiles were launched from an Iranian military facility about 12 km from the plane.
She added that none of the missiles immediately fell, and that the video showed that the plane had caught fire and returned to Tehran airport.
The story began when the Iranian air defenses brought down the plane when the armed forces were on alert in anticipation of an American response after mutual military strikes in the latest escalation of a crisis that has continued for years due to Iran's nuclear program.
The Revolutionary Guards claimed responsibility for the missile strike that brought down the plane, killing all 176 people on board.
The military and other senior officials have apologized strongly for the shooting down, which they described as an "unforgivable error", and said they would try those responsible in an attempt to calm the public outrage.
The plane disaster and the turmoil that followed pressures on the regime in Iran, which is facing difficulties in keeping the country's economy from collapsing, intensified, under the weight of strict US sanctions imposed by Washington after its withdrawal from the nuclear agreement concluded by Iran with world powers.
Most of the plane's victims are Iranian or dual nationals, many of whom are students who are returning to continue their studies abroad after visiting their families on vacation.
After the authorities acknowledged - after being denied for days - the downing of the Ukrainian passenger plane last week, protesters, mostly students, organized daily protests in Tehran and other cities from last Saturday to today.
While calls appeared on social networking sites on Wednesday for new demonstrations, seeking to turn the protests that followed the crash into an ongoing campaign against the Iranian leadership.
For its part, Ukraine said that London hosted Thursday a meeting that included representatives of Canada, Ukraine, Britain and other countries with nationals among the victims of the plane, to discuss legal action against Iran.
Iranian media reported that Canada, which killed 57 of its citizens in the plane crash, sent investigators to Iran who inspected the crash site on Tuesday.