The Islamic State took credit for yesterday’s suicide attack outside of Afghanistan’s supreme court which killed at least 20 people and wounded dozens more. The attack was executed by a Tajik fighter, the group claimed.

The Islamic State’s Khorasan province, the group’s branch in Afghanistan and Pakistan, claimed the attack in a statement released today. The statement was obtained and translated by the SITE Intelligence Group. The suicide bomber was identified as “Abu Bakr al-Tajiki,” according to SITE.

“He detonated his vest amidst a gathering of judges and stuff [sic] in the court, which resulted in killing and wounding nearly 60 apostates,” the Islamic State said. Independent press reports from Afghanistan indicated that 21 people were killed and more than 40 were wounded; “17 of those killed were employees of the Supreme Court – including nine women,” according to TOLONews.

The Islamic State threatened further attacks against Afghan courts and judicial personnel.

“Let the apostates [those who support the Afghan government], and at their head the judges of the tyrants, know that the disbelieving judgments they issue against the monotheist mujahideen serve the Crusaders and will not pass without severe punishment, Allah permitting, and what is coming is more devastating and bitter,” according tot he SITE translation.

The Afghan court system has previously been attacked by the Taliban, which overshadows the rival Islamic State’s Khorasan province.

In June 2013, a nearly identical attack was claimed by the Taliban at the exact location. A Taliban suicide bomber killed at least 16 civilians, including employees who worked at the supreme court in Kabul, when he detonated in the very same parking lot outside of the supreme court.

Additionally, in Jan. 2009, the Afghan Ministry of Justice in Kabul was the target of a deadly Taliban suicide assault which also included a separate attack on the Education Ministry and a prisons office in the capital. At the Justice Ministry, where the heaviest fighting took place that day, a suicide bomber detonated at the main gate, allowing three other attackers armed with AK-47s and hand grenades to enter the compound and the ministry building. Gunfights broke out as the attackers battled security guards in the hallways.

Unlike the Taliban, the Islamic State’s Khorasan province has limited resources inside of Afghanistan, as it commands only a small fraction of the jihadist insurgency. Khorasan province is led by disaffected Taliban commanders from both the Afghan and Pakistani Taliban as well as others from marginalized jihadist groups. The group is thought to have several thousand fighters, versus tens of thousands of fighters in the Taliban. Khorasan province has a presence in several provinces, but is based in Nangarhar. The group has been been weakened since it declared war on the Taliban and lost multiple battles.

The Tajik suicide bomber who launched yesterday’s attack was likely a member of the Islamic Movement of Uzbekistan (IMU), a jihadist group based in Afghanistan, Pakistan, and Central Asia. An IMU faction, led by the group’s emir, joined Khorasan province and swore allegiance to Islamic State emir Abu Bakr al Baghdadi in 2015. The merger was denounced by senior jihadist leaders, including the group’s top religious figure.

The IMU was part of a web of jihadists groups that US military officials used to refer to as the Kabul Attack Network, which pooled resources to launch major assaults in and around the Afghan capital.

Bill Roggio is a Senior Fellow at the Foundation for Defense of Democracies and the Editor of FDD's Long War Journal.

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