Gunmen stormed two major sites in the Iranian capital Wednesday, opening fire and detonating suicide blasts in parliament and at the revered tomb of the nation’s Islamic revolution leader. The Islamic State claimed responsibility for the Tehran attacks, which would mark the group’s first major strikes in Iran.

The state news agency IRNA said at least two security guards were killed and about 30 people were wounded. Hours after the attacks, parliament was still in lockdown with some of the attackers still battling security forces.

The Islamic State group’s media arm Amaq claimed the militant group carried out the twin attacks. The Islamic State, however, is often quick to take ownership of spectacular assaults without providing any evidence.

Iran is a predominantly Shiite Muslim country and is at odds with Sunni extremist groups such as al-Qaida and the Islamic State, which it is battling, together with its proxies, in Iraq and Syria.

Attacks of this kind are a rarity in the heart of Iran’s capital, where security forces are deployed at prominent sites. The parliament building, with a green marble chamber for lawmakers, is in the center of the city, and the tomb complex for Ayatollah Ruhollah Khomeini is about 12 miles to the south near the international airport.

“Some coward terrorists infiltrated a building in the Majlis, but they were seriously confronted,” parliament’s speaker, Ali Larijani, told IRNA. “This is a minor issue but reveals that the terrorists pursue troublemaking.”

Iranian intelligence, meanwhile, said they had foiled a third attack and arrested a team, according to the state broadcaster. The statement from the Islamic State did not mention a third attack.

Ali Khalili of the Khomeini Mausoleum told IRNA that there were at least three, possibly four, attackers who opened fire on the tomb, and one of them detonated himself at the entrance.

Lawmaker Qolam-Ali Jafarzadeh Imenabadi, meanwhile, put the number of attackers at the parliament at four and said they were armed with Kalashnikov assault rifles.

One of the attackers at the parliament was arrested, added the news agency and another blew himself up with a suicide vest.

The remaining attackers were described as “under siege.”

The Associated Press cited witnesses on the scene who heard gunfire from the parliament building directed at the streets below while police helicopters circled the scene.

Despite unconfirmed reports of a hostage situation, the parliament’s spokesman Mahdi Kiaie insisted that everything at the parliament was now under control with units of the Revolutionary Guard securing the building.

Iran has suffered from terrorist attacks in the past, but rarely in the cities or the capital. Separatist groups and Sunni extremist movements have carried out bombings in the border region near Pakistan in the past, including a suicide attack on a mosque in 2010 that killed 39.

The violence in Tehran added to swelling sense of bedlam and instability across the Persian Gulf region. In addition to the civil war raging in Yemen and the ongoing war in Iraq against the Islamic State militant group, Saudi Arabia and other Arab nations announced this week they were severing virtually all ties with the government of Qatar because of what they said was Qatar’s support for terrorist groups.

The extraordinary rift between the Saudi-led bloc and Qatar showed the degree to which Iran’s increasingly muscular role in the region – including its intervention in Syria’s civil war – has stirred fury among its Arab rivals. Saudi Arabia and its Sunni allies, including Bahrain and the United Arab Emirates, have expressed growing anger at Qatar’s relatively cordial relations with Shiite Iran.

The Washington Post’s Kareem Fahim in Istanbul contributed to this report.