Iran has criticized the Netherlands, Denmark and Britain for hosting "members of the terrorist group" which it says carried out Saturday's shooting at a military parade in the south of the country.
In the hours after a suspected terrorist attack on a military parade in the Iranian city of Ahvaz on Saturday left more than two dozen dead, countries from around the world offered their sympathies to the victims. The attack was claimed by an Ahvaz separatist group on an opposition televisioini station based in London by a spokesman based in Copenhagen.
General Hossein Salami, acting head of the Revolutionary Guard, said at a mass funeral in Ahvaz: "You have seen our revenge before".
"You have seen our revenge before ..."
US Defense Secretary James Mattis on Monday wrote off Iranian threats to avenge a deadly attack on an Iranian military parade and called allegations of US involvement "ludicrous".
A video released by the IS-affiliated Amaq news agency showed three men in a vehicle who appear to be dressed in IRGC uniforms.
"It is unacceptable that these groups are not considered to be terrorist groups by the European Union provided they do not commit acts of terror in Europe", Iranian foreign ministry spokesperson Bahram Qasemi said. The United States has condemned the attack. "Iran is not the place for such [terrorist] activities", Alav said. Many held pictures of a four-year-old boy killed in the incident, one of the worst such attacks against Iran's most powerful military force.
At least eight of those killed were Revolutionary Guards personnel.
The harsh statement came as bodies of those killed in the attack were laid to rest in Iran's southwestern city.
Khamenei earlier accused US-backed Gulf states of being behind the attack, saying in a statement that "this crime is a continuation of the plots of the regional states that are puppets of the United States".
The competing claims and blame have only clouded understanding of who was responsible for the attack but Iran's anger at the USA has come after long-term American support for anti-government groups has shifted towards more open hostility, with members of Donald Trump's administration supporting regime change. Iran accuses Saudi Arabia and the UAE of doing the same in Khuzestan.
He said: "America wants to cause chaos and unrest in our country so that it can return to this country, but these are unreal fantasies and they will never achieve their goals".
But citing "reports" by Iran's government, the ayatollah said on Monday, "the cowardly attack was committed by those who are rescued by the Americans whenever they are locked in Syria and Iraq, and they are financed by Saudi and Emirate's money", according to the state-run IRNA news agency.
The senior commander of the Islamic Revolution Guards Corps, Brig.
The Revolutionary Guard is a paramilitary force answerable only to Supreme Leader Ayatollah Ali Khamenei.