More than 100 people were killed Wednesday when two bombs exploded during a commemoration service near the gravesite of Qasem Soleimani, the former leader of the country’s Quds Force outfit, in the city of Kerman.

“We were walking towards the cemetery when a car suddenly stopped behind us. and a waste bin containing a bomb exploded,” an eyewitness told the Iranian Students’ News Agency (ISNA). “We only heard the sound of the explosion and saw people falling.”

Soleimani was targeted by American drones in January 2020 near Baghdad. He was a senior Iranian military official who was responsible for the architecture of the nation’s alliances across the region, bolstering terror groups such as Hamas and Hezbollah as well as militias in Syria and Iraq.

Iranian supreme leader Ayatollah Ali Khamenei denounced Wednesday’s explosions as a “terrorist attack” and vowed a “harsh response,” though he avoided naming any specific actor or nation. President Ebrahim Raisi called the blasts a “cowardly act” perpetrated by “Iran-hating criminals and the henchmen of terror and darkness.”

“The evil and criminal enemies of the Iranian nation once again created a disaster and martyred a large number of dear people in Kerman,” Khamenei said in an official statement released Wednesday. “Be it those with innocents’ blood on their hands or those corrupt minds that led to this atrocity, they will be met with firm crackdown and fair punishment, commencing immediately. They should know that this disaster will have a harsh response, God willing.”

The bombs were detonated by “remote control,” an unnamed source told Tasnim, a media outfit associated with the Islamic Revolutionary Guard Corps (IRGC).

The blasts come on the heels of a Christmas Day strike on senior IRGC officer Brigadier General Razi Mousavi in the Syrian capital of Damascus. Although Israel has not claimed responsibility for the assassination, Iran has vowed to retaliate against the Jewish State. “Without a doubt, this action is another sign of frustration, helplessness, and incapacity of the usurping Zionist regime in the region,” President Raisi said following the news.

However, some Israel watchers believe the fingerprints of this attack suggest other actors. “There is no way that Israel would have carried out an attack like this. The attacks [in Iran] that are always blamed on Israel are surgical actions in which citizens are not hurt,” former senior Shin Bet officer Yaron Bloom told Channel 12 news. “This is an attack characteristic of Islamic State.” Ali Vaez, an Iranian specialist with the Crisis Group think thank, concurred in comments to the New York Times.

Tensions between the two nations have escalated since Hamas invaded Israel on October 7 and committed widespread atrocities with planning assistance from Iran. Over the intervening months, Iranian-backed proxies have struck American targets and sought to further destabilize the region. One such group, the Houthis in Yemen, have attacked international shipping routes trying to stanch the flow of trade through the Suez Canal.