On Wednesday morning, the Islamic State carried out an unprecedented double terrorist attack on Iran’s Parliament building and the iconic shrine of the late founder of the Islamic Republic and leader of the 1979 revolution, Ayatollah Ruhollah Khomeini, leaving at least 12 people dead and 42 others injured.

The deadly siege went on for over four hours. The militants seemingly targeted those two specific landmarks to send a message to the Shiite government of Iran.

This is the fourth attack the Islamic State has claimed since the start of the Muslim holy month of Ramadan, which began on May 27. The previous three include attacks on London, England; Manila, Philippines; and Baghdad, Iraq. The government of the Philippines has rejected ISIS’s claim on the Manila attack, however, stating the perpetrator had no ties to Islam at all. Wednesday’s attack on Tehran is the first time the Sunni Islamic State has taken carried out an assault in a Shiite-majority country.

Iran’s deputy interior minister, Mohammad Hossein Zolfaghari, said the terrorists entered Parliament wearing women’s clothing and wielding Kalashnikov rifles.

Another group of terrorists reportedly entered Khomeini’s iconic shrine where two Islamic State militants blew themselves up as others embarked on a bloody shooting spree. At least one Iranian security guards died in the suicide bombings.

According to the Independent, the terrorists could be heard shouting in Arabic, as gunshots and alarms rang in the background, “Oh God, thank you… Do you think we will leave? No! We will remain, God willing.” Those words were reportedly popularized by Islamic State spokesman Abu Mohammad al-Adnani, who was killed in Syria last year.

In a statement released by the Islamic State’s Amaq News Agency, the group said, “The two martyrdom operatives blew themselves up inside the Khomeini mausoleum in the center of Tehran.”

A video clip believed to have been taken by one of the attackers inside Iran’s Parliamentary building was posted to YouTube:

Both Iranian security and the Islamic Revolution Guards Corps (IRGC) reportedly killed the four terrorists who attacked the parliament building. The Shargh Daily included a picture of one of the Islamic State militant’s bodies:

According to the IRIB news agency, one of the men injured in the attack on Parliament said, “We weren’t allowed to bring a pen into Iran’s Parliament, but attackers easily fired [at] us in the building.”

Iran’s state Press TV tweeted an image of a security guard helping a child escape the Parliament building through a window:

“In recent days on the anniversary of Imam Khomeini’s death the shrine was very crowded and perhaps these gunmen have wanted to send a message that they can carry out such an attack in a place like that,” Azad Muhammadiyani, an MP and head of the United Kurdish Front told Kurdish news agency Rudaw. He added, “And the parliament is the place of legislation and passing laws and therefore the gunmen may have wanted to send this message too. ISIS has always wanted to sneak into Iran and the intelligence ministry has been reporting in the past three years how they have been foiling ISIS plans inside the country.”

Iran did not waste time blaming the Sunni-majority nation of Saudi Arabia for the attacks. Iran’s Fars News Agency wrote a piece titled, “Saudi deputy crown prince intimidates Iran weeks before Tehran terrorist attacks.”

According to IRIB news, Iran’s Parliament Speaker Ali Larijani called the attack a cowardly act. “Iran is an active and effective pillar in the fight against terrorists, and they want to damage it,” he reportedly said. After he finished speaking, his fellow parliamentarians began shouting “Death to America” while pumping their fists in their air.

Adelle Nazarian is a politics and national security reporter for Breitbart News. Follow her on Facebook and Twitter.