The Islamic State has struck at Iran and its allies for years — but always from afar, in places such as Iraq against Tehran-backed militias and in Syria battling government troops aided by Iranian forces.
The twin attacks, the first major assaults in Iran claimed by the Islamic State, targeted the heart of Iran’s political identity and the notion that militants were no match for the security forces zealously guarding Tehran.
At least 12 people were reported killed and 42 wounded in the assaults in the parliament building and outside the tomb of the leader of the nation’s Islamic revolution. Security forces eventually killed all four assailants, state media reported. Hours later, Tehran’s police chief said five suspects had been detained and were being interrogated.
While the attacks showed that the United States and Iran have a shared enemy, they appeared unlikely to reset U.S.-led efforts against the Islamic State or bring Iran more directly into the fight — especially since the Trump administration has embraced Iran’s main regional foe, Saudi Arabia, as a bulwark in fighting Islamist militants and constraining Iran’s regional influence.
In a White House statement, President Trump said Wednesday: "We grieve and pray for the innocent victims of the terrorist attacks in Iran, and for the Iranian people, who are going through such challenging times. We underscore that states that sponsor terrorism risk falling victim to the evil they promote."
The Washington-based National Iranian American Council promptly rebuked what it called Trump’s “heartless message,” saying that presidents who “cannot genuinely recognize victims of terrorism are incapable of leading the fight against terror.”
Iran's powerful Revolutionary Guard Corps took a thinly veiled jab at Saudi Arabia as a source of militant ideology, saying it was "meaningful" that the attacks occurred less than three weeks after Trump visited Riyadh and asserted strong U.S. support for the Saudis and their allies.
The Revolutionary Guard statement added that the “spilled blood of the innocent will not remain unavenged.”
Iran is predominantly Shiite Muslim and is at odds with Sunni extremist groups such as al-
Qaeda and the Islamic State, which view Shiites as heretics and have attacked Shiite targets across the region.
While it is unclear what direct measures Iran could take against the Islamic State, the fallout is certain to deepen regional tensions at a difficult time. Secretary of State Rex Tillerson and others have pledged to try to heal an unprecedented diplomatic break in which Saudi Arabia and its allies have severed ties with Qatar, a key U.S. military partner in the Persian Gulf.
The scene after gunmen stormed the parliament in Tehran
The Saudis and their allies accuse Qatar of supporting Islamist militants and oppose its outreach to Iran.
For the Islamic State, striking directly at Iran appears to be part of a wider attempt to stir regional discord.
An attack inside Iran was “absolutely the realization of a long-term ideological goal” for the Islamic State, said Charlie Winter, a senior research fellow at the International Center for the Study of Radicalization at King’s College in London.
“Ideologically, the implications are huge,” he said. “Attacking Iran is kind of like attacking the U.S. or Israel.”
The near-simultaneous attacks — coming in the middle of the Islamic holy month of Ramadan — also appeared calculated to elicit maximum shock among Iranians.
The parliament is widely respected as a voice on domestic policies even though Iran’s supreme leader, Ayatollah Ali Khamenei, has the final word on most international and security issues. The shrine of Khamenei’s predecessor, Ayatollah Ruhollah Khomeini, is a centerpiece of homage to the 1979 Islamic revolution, which overthrew Iran’s Western-allied monarchy.
The timing, meanwhile, could have been intended to boost the Islamic State's stature among backers as it faces a two-pronged assault against its key urban strongholds: Mosul in northern Iraq and Raqqa in Syria. An expanded offensive by U.S.-backed forces against Raqqa, the Islamic State's de facto capital, began Tuesday.
“It is indeed a boost to ISIS morale, especially given that it’s the first successful attack in Iran,” said Dina Esfandiary, who studies global security issues at the Center for Science and Security Studies at King’s College. The Islamic State is also known as ISIS.
Iranian state TV quoted Khamenei as dismissing the attacks as mere “fireworks” that would not weaken Iran’s fight against groups such as the Islamic State.
The Islamic State’s Amaq News Agency claimed that the group carried out the attacks. The Islamic State, however, is often quick to take ownership of spectacular assaults without providing evidence.
But the news agency also circulated a 24-second video that purported to show a fighter walking near a body during the attack on the parliament.
“Oh, Sunni people in Iran, don’t you feel the pain from those shackles that are tied around your wrists and ankles?” one militant said in the video, calling on Sunnis to wage battle against Shiites in their “dens and gatherings” in Tehran and other Iranian cities.
The Islamic State also began distributing its online magazine Rumiyah in Persian late last month.
Iran views its parliament, or Majlis, as a symbol of participatory government in contrast with its main regional rivals, including Saudi Arabia and allied sheikhdoms in the Persian Gulf. Last month, Iran’s president, Hassan Rouhani, won reelection in a race against hard-line challengers.
“The parliament has very specific meaning for Iran after the recent election. Its democracy was attacked,” said Marc Martinez, a senior analyst and Iran expert at the Delma Institute, a political consultancy in Abu Dhabi in the United Arab Emirates.
The expansive complex around Khomeini’s tomb is a spiritual and political testament to the Islamic revolution. The huge courtyard and buildings, including blue-tiled domes that tower over the mausoleum, are particularly filled with visitors during Ramadan, which began two weeks ago.
Attacks of this kind are rare in Iran’s capital, where security forces are deployed at prominent sites. The Revolutionary Guard Corps also maintains a vast network of informants and allies through a volunteer paramilitary force called the Basij.
The parliament building is in the center of the city, and Khomeini’s tomb complex is about 12 miles to the south.
Iran has suffered terrorist attacks in the past but rarely in cities or the capital. Separatist groups and Sunni extremists have carried out bombings in the border region near Pakistan, including a suicide attack in 2010 that killed 39.
Paul Schemm in Addis Ababa, Ethiopia; Loveday Morris in Irbil, Iraq; and William Branigin and Carol Morello in Washington contributed to this report.