Saudi Arabia has denied responsibility for the attacks.
Two separate attacks shook Tehran on June 7. The four-minute video shows three masked men sitting on a floor holding automatic rifles. The reports said Iran's security forces neutralized one terrorist, another one committed suicide there.
"This is a message from the soldiers of Islamic State in Iran, soldiers of the first brigade of Islamic State in Iran which, God willing, won't be the last", the leader says. He speaks out at length against Shiites and promises further attacks.
The attacks came at a particularly charged time in the region, days after Saudi Arabia and other Arab countries cut ties with Qatar, accusing it of backing Tehran and militant groups. It called the detainees "elements of the Wahhabi ISIS group", and said they were involved in operations, communication and logistics for the local Islamic State group cell. State TV broadcast the ceremony live.
In making the comments, the parliament speaker was referring to the recent trip to Riyadh by President Donald Trump, during which he signed a $100-billion arms deal with the Saudi side.
As thousands of mourners gathered on Friday for the funeral of the victims of the twin terrorist assault in the capital Tehran, senior Iranian authorities pledged to remain adamant in their anti-terrorism cause.More news: Passengers create impromptu graduation ceremony for student stuck on subway
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Trump issued a statement after the attack offering condolences for the victims, while also taking a swipe at Iran.
Pope Francis "laments this senseless and grave act of violence", and "assures the people of Iran of his prayers for peace", the message read.
Today, the Intelligence Ministry announced that it had detained 41 suspects in Tehran and the western Kurdish provinces.
Two terrorist groups attacked mausoleum of the late Imam Khomeini and the Iranian Parliament on Wednesday morning (June 7), killing 17 people and injuring 52 more.
Alavi said that in the last month the intelligence ministry had identified and crushed "a terrorist team" nearly every day but had not publicized it to avoiding spreading fear among the public.