TEHRAN, Iran _ Iran suffered its worst terrorist attack in recent memory Wednesday, a bold strike by assailants armed with explosives and assault rifles against the tomb of the Islamic Republic's revolutionary founder and the parliament building that killed at least 12 people and injured 42 others.
The militant group Islamic State claimed responsibility via its Amaq news agency, saying the near-simultaneous attacks were carried out by "martyrdom-seeking fighters with two explosive vests." If true, it would be the Sunni Muslim extremist group's first successful attack in Shiite-led Iran, a nation it regards as a leader of apostates.
Iran's powerful Islamic Revolutionary Guard Corps put the blame on Saudi Arabia and the United States, which have stepped up their alliance against Tehran and its nuclear ambitions.
Parliament was in session when assailants armed with Kalashnikov rifles and explosives stormed the building around mid-morning, said Deputy Interior Minister Mohammad Hossein Zolfaghari. At least one was disguised as a woman, according to witnesses.
Even as that attack was underway, gunmen and suicide bombers struck outside the shrine of Ayatollah Ruhollah Khomeini, a venerated gathering spot for Shiite faithful on the southern edge of Tehran.
Of the eight attackers, six were killed and two arrested, according to the semi-official Fars news agency.
The assault came at a sensitive time in the Persian Gulf, where several leaders, emboldened by President Donald Trump's recent visit to Saudi Arabia, severed ties this week with Qatar, the one Arab country in the region that maintains relations with Iran. It also came the day after a U.S.-backed alliance of Syrian Kurdish and Arab militias announced the start of a long-awaited assault city of Raqqah, Islamic state's self-styled capital in Syria.
The militants released a graphic video of the attack. "Do you think we will go away?" a narrator asks. "We are here to stay, God willing."
The Revolutionary Guard noted in a statement that the attacks happened shortly after Trump's meeting with "one of the reactionary rulers of the region," an apparent reference to Saudi King Salman.
It called the timing "a meaningful coincidence," and said Islamic State's claim was further evidence that "the American president and the reactionary ruler are involved in this brutality."
The assault drew swift condemnation and expressions of condolence from countries such as Syria, Pakistan, and Russia.
Hours later, Trump issued a two-sentence statement in which he said, "We grieve and pray for the innocent victims of the terrorist attacks in Iran, and for the Iranian people."
But Trump suggested that Iran shared in the blame, warning that "states that sponsor terrorism risk falling victim to the evil they promote."
The Trump administration has made Iran the focus of its anti-terrorism rhetoric and policies, apparently creating a quandary for how to respond when Iran itself is the target of an attack.
The U.S. has long considered Iran to be a sponsor of terrorism outside its borders. Yet Tehran has been active in the fight against Islamic State, another stated priority of the administration.
The State Department also issued a brief statement, saying: "The depravity of terrorism has no place in a peaceful, civilized world."
But it pointedly did not express solidarity with Iran's government or offer assistance. Separately, the Senate voted overwhelmingly Wednesday to advance a bill that would impose new sanctions on Iran over its ballistic missile program and supply of weapons to militant groups.
Iran's supreme leader, Ali Khamenei, played down the significance of the attacks, saying, "These fireworks have no impact on the will power of the people." But experts said they were bound to cause alarm, especially as the country's leadership had assured residents that fighting Sunni militants in Iraq and Syria would keep them from attacking the Islamic Republic.
The militants "have attacked the beating heart, the nerve center of the Islamic revolution," said Fawaz Gerges, a professor of international relations at the London School of Economics. "For many Iranians, now, they are on our streets."
The siege at parliament lasted about three hours, and it appeared that not all lawmakers were aware of the extent of the violence at first.
Heshmatollah Falahatpishe, a member of parliament, said lawmakers were in regular session when a couple of colleagues arrived at about 10:15 a.m with bloodstains on their clothing.
"Daesh has attacked,'" Falahatpishe recalled them saying, using a common Arabic acronym for Islamic State. "We continued ... discussions until 1 p.m., when we heard the shooting."
He said his bloodstained colleagues told them the attackers had entered the building through the western gate, through which constituents normally enter to meet with members of parliament. At least one of the attackers appeared to be dressed in the traditional black robe worn by many Iranian women.
"The terrorist wrapped up in a black chador and carrying a gun entered, shot the gate guard and opened the gate for his fellow terrorists," Falahatpishe said. "They started shooting."
After after 1 p.m, an elite law enforcement force stormed the building and lawmakers were able to leave through the southern gate, he said.
Mohammad Ali Saki, editor of the English-language Tehran Times, said four assailants attacked an administrative building next to parliament, targeting guards, cleaners, and other employees, but never got near the parliament chamber.
"The main door where parliamentarians enter has not been targeted," Saki said.
Police initially directed the city's 14 million residents to avoid the downtown area and public transportation, Saki said. Those orders were lifted late Wednesday, but people did not immediately return to the streets.
"The people are both angry and concerned because we are the only country in the region that had remained safe from the vicious acts of terrorism," he said, noting that officials disrupted several terrorist networks last year.
"Unfortunately, they succeeded in attacking the symbols of the country, of democracy and what is cherished by the people, the shrine of the founder of the Islamic Republic."
After the end of the siege, Parliament Speaker Ali Larijani made a defiant address to lawmakers.
"This morning a few terrorists committed a cowardly terrorist action, were seriously brought down, and parliamentarians are doing their normal jobs," he said. "Iran is a pillar in fighting terrorism. They want to make a problem, but the problem will be solved."
Terrorist violence is rare in the Iranian capital, where state security forces keep a tight grip, although analysts have said Tehran's support for Syrian President Bashar Assad could make Iran a target for supporters of Islamic State.
The extremist group is at war with Iranian-backed groups in Syria and Iran and views Iran's Shiite majority as apostates deserving of death.
