ISIS is celebrating the apparent terrorist attack in Nice, France, on Thursday as retaliation for the death of Abu Omar al-Shishani—the terror group’s so-called “minister of war”—who was killed earlier this year by coalition forces while fighting in Iraq.

More than 70 people were killed and dozens more were injured when a truck barreled through a large crowd of people celebrating Bastille Day, a French holiday commemorating the storming of the famous Parisian fortress in 1789, an important milestone in the French Revolution. The driver of the truck reportedly was killed by French authorities.

“Oh France, you and the all Europe will never be secure until we will live secure on every inch in the land of the Caliphate,” wrote one ISIS supporter whose Twitter account has since been suspended. “This is the beginning of the attack to take the holy revenge for the killing of Abu Omar Shishani, may Allah accept him,” a jihadi posted on the ISIS al-Minbar forum shortly after the attack.

لن تأمني بالأمان يا فرنسا وجميع اوروبا حتى نعيشه واقع في كل شبر من ارض الخلافة #نيس — همي رضى ربي286 #منبج (@abomusaab_286) July 14, 2016

(Translation: “Oh France, you and the all Europe will never be secure until we will live secure on every inch in the land of the Caliphate.”)

ISIS supporters have created a hashtag that translates to “#the attack on the name of Omar Shishani.” Perhaps unsurprisingly, a top U.S. official tells The Daily Beast that ISIS is already a top suspect in the attack.

More Nice Residents Open Doors After Truck Attack

ISIS militants have been urging supporters to run westerners over with vehicles since 2014, when Abu Mohammed al Adnani, a spokesman for the Islamic State, urged the group’s supporters to kill “disbelieving American or European – especially the spiteful and filthy French – or an Australian, or a Canadian, or any other disbeliever from the disbelievers waging war, including the citizens of the countries that entered into a coalition against the Islamic State, then rely upon Allah, and kill him in any manner or way, however it may be,” he said in 2014. “Smash his head with a rock, or slaughter him with a knife, or run him over with your car, or throw him down from a high place, or choke him, or poison him.”

The Pentagon announced earlier this year that they believed Shishani, a Chechan-born jihadist known as Omar the Chechen, was likely killed in a U.S.-led airstrike in Syria. On Wednesday, Amaq, a media outfit that regularly publishes official news on behalf of ISIS, announced that Shishani was killed while fighting in Shirqat, Iraq, a city south of Mosul.

Shishani was a trusted military advisor to ISIS Leader leader Abu Bakr al-Baghdadi and previously had a $5 million bounty on his head. At one point, he was one of the U.S. government’s top five most wanted jihadists.

The Iraqi military is currently preparing to launch a campaign backed by U.S. warplanes and special forces to recapture Mosul, Iraq’s second largest city that was overtaken by ISIS fighters in 2014. On Monday, the Pentagon announced that President Obama planned to send an additional 560 U.S. troops to help with the offensive.