Iran summoned diplomats from three European countries late Saturday in the wake of a deadly attack on a military parade that it blamed on "a foreign regime."
The Danish and Dutch ambassadors and the British charge d'affaires were summoned, the Iranian news agency IRNA reported Sunday.
The al-Ahvazieh militant group claimed responsibility for the attack on the parade on Saturday in the city of Ahvaz, in which at least 25 people were killed and 60 others injured, including children, IRNA said.
The Iranian leadership charged that Denmark, the Netherlands and Britain have harboured members of the militant group.
The fact that the EU did not black-list the militants as long as they had committed no crimes in Europe was unacceptable, Foreign Ministry spokesman Bahram Ghassemi was quoted as saying.
"Why are attacks in Europe given so much attention but not elsewhere," he added.
The Danish ambassador to Iran, Danny Annan, confirmed that he had attended a meeting at the Foreign Ministry in Tehran late Saturday, Danish broadcaster TV2 reported. No further details were given.
The Foreign Ministry in Copenhagen did not respond to dpa's request for comment.
Supreme Leader Ayatollah Ali Khamenei blamed the attack in Ahvaz on what he termed "a conspiracy of US-supported regimes in the region" who sought to foment instability in Iran.
The Revolutionary Guards are a paramilitary force led by Khamenei that sees itself as custodians of the Islamic Republic.
Saturday's parade was held to mark the start of the Iran-Iraq war in 1980. Similar events were held around the country.