When Tehran was struck by deadly ISIS attacks in June, President Donald Trump took the opportunity to blame Iran's government.
Deputy Chief of Staff of Iranian Armed Forces Major General Mostafa Izadi said Tehran has evidence of the U.S.'s "direct support" for the Islamic State militant group.
The attacks in the Iranian capital striking the country's parliament and a shrine killed 17 people.
Iran's Intelligence Ministry said Wednesday's massacre was perpetrated by Iranians loyal to the Islamic State militant group who fought in Iraq and Syria.
The Islamic State militant group claimed responsibility for twin attacks in the Iranian capital that killed 13 people.