Iranian President Hassan Rouhani Saturday said his country "deeply regrets" the shooting down of a Ukrainian airliner, which he described as "a great tragedy & unforgivable mistake".
"Armed Forces' internal investigation has concluded that regrettably missiles fired due to human error caused the horrific crash of the Ukrainian plane & death of 176 innocent people," he added on Twitter.
"Investigations continue to identify & prosecute this great tragedy & unforgivable mistake."
Iran announced Saturday that its military 'unintentionally' shot down a Ukrainian jetliner, killing all 176 aboard.
The statement came Saturday morning and blamed "human error" for the shootdown.
The jetliner, a Boeing 737 operated by Ukrainian International Airlines, went down on the outskirts of Tehran during takeoff just hours after Iran launched a barrage of missiles at US forces.
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.
The Kiev-bound Ukrainian Boeing 737 passenger plane crashed on Wednesday three minutes after taking off from Tehran airport.