On Friday, Kabul was rocked by a violent attack on the 25-year anniversary of the death of ethnic minority leader Abdul Ali Mazari.

The event was attended by several government officials and politicians, including former Afghan president Hamid Karzai and former presidential candidate Abdullah Abdullah. Gunmen stormed the event during the speeches.

The scale of today’s tragedy is still unclear. Afghanistan’s Pajhwok Press Agency reports 18 injuries, while the BBC and Al Jazeera are reporting 27 casualties and 29 wounded.

The attack marks a return to violence on the streets of Kabul, the first major attack since the recent deal between the United States and the Taliban. Although the ceremony memorialized a Shia minority leader who was killed in 1995 by the Taliban, it is unclear who is responsible for the attack.

The Taliban had agreed to a week-long “reduction of violence” as part of the recent deal with the U.S. The temporary truce ended when three people were killed, and 11 injured, in Eastern Afghanistan earlier this week. Although the Taliban has committed to not attack ‘foreign’ forces, the conflict with the Kabul government continues unabated.

The Taliban released a statement shortly after the attack, denying their involvement.

Last year, the same memorial was attacked by an ISIS-affiliated group, raising speculation that Friday’s attack was motivated by resentment toward the ethnic Hazara minority, who are primarily Shia.

On Monday the Guardian reported that Mark Milley, the chairman of the joint chiefs of staff in Afghanistan, warned that violence would not be “going to go to zero,”especially as “the Taliban is not a monolithic group.”

NATO representative Ambassador Kay published a statement condemning the attack: 

“I condemn today’s attack on the #AbdulAliMazari commemoration in #Kabul leaving many dead & injured. My thoughts are with the victims’ families, wishing speedy recovery to the wounded. We will continue to support the ANDSF in the fight against terrorism.”

The attack further underscores the difficult road towards peace in Afghanistan. The United States and the Taliban have made agreements that differ from agreements with the Kabul government, and little progress appears possible as violence continues to flare up.