Iran admits to 'unintentionally' shooting down plane
Iranian Foreign Minister Javad Zarif tweeted "human error" was to blame for the downing of the passenger jet.
"Our profound regrets, apologies and condolences to our people, to the families of all victims, and to other affected nations," he said.
A statement read on state television said the airliner had flown close to a sensitive military site and the responsible parties will be held accountable.
The jetliner, a Boeing 737 operated by Ukrainian International Airlines, went down on the outskirts of Tehran during take-off, just hours after Iran launched a barrage of missiles at US forces.
Iran had denied for several days that a missile downed the aircraft.
But then the US and Canada, citing intelligence, said they believed Iran shot down the aircraft.
The plane, en route to the Ukrainian capital of Kyiv, was carrying 167 passengers and nine crew members from several countries, including 82 Iranians, at least 63 Canadians and 11 Ukrainians, according to officials.