VATICAN CITY — After twin terrorist attacks killed at least 17 people in Tehran, Iran, earlier this week, Pope Francis condemned the “barbaric” act of violence and offered his prayers for the victims and their families.  

“His Holiness Pope Francis sends his heartfelt condolences to all those affected by the barbaric attack in Tehran and laments this senseless and grave act of violence,” a June 9 letter signed by Vatican Secretary of State Cardinal Pietro Parolin read.

“In expressing his sorrow for the victims and their families, His Holiness commends the souls of the deceased to the mercy of the Almighty, and he assures the people of Iran of his prayers for peace.”

On Wednesday, June 7, deadly attacks on Iran’s parliament building and a monument containing the tomb of the republic’s founder, Ayatollah Ruhollah Khomeini, killed nearly 20 people and wounded several others.

According to CNN, six attackers simultaneously carried out gun and suicide bomb assaults around 10am local time. The violence began when four of the gunmen, allegedly dressed as women, stormed the gate of the parliament building and opened fire.

The assailants took several hostages before one detonated a suicide bomb. Sporadic gunfire was heard before Iranian security forces eventually killed all four of the attackers.

Also called the Islamic Consultative Assembly or Majlis, Iran’s parliament is the country’s main legislative body. It has a total of 290 members, including women and representatives of minority religions, such as Christians and Jews.

At the same time as the parliament attack, two gunmen went on a shooting spree at the Ayatollah Khomeini mausoleum, which is located roughly 15 miles away and is a popular destination for tourists and pilgrims.

Khomeini, the Iranian Republic’s founder and first supreme leader, led the revolution that overthrew the shah in 1979 and remained the supreme leader of the republic for the next 10 years.

ISIS militants claimed responsibility for the attack, marking the first time the organization, a Sunni Muslim group fighting Iranian-backed forces in Syria, took responsibility for an attack in Iran, a predominantly Shiite nation.

The last major attack in Iran took place in 2010, when a Sunni extremist group launched a suicide attack against a mosque in Sistan-Baluchistan that killed 39 people.

The Tehran attack was the latest in a string of terrorist attacks claimed by ISIS in recent days.