ISIS claims responsibility for NYC terror attack, calls driver 'soldier of the Caliphate'

The group proudly noted the "fear and panic" the attack inspired.

— -- The Islamic State claimed responsibility on Thursday for the deadly Halloween day terror attack in New York City in the group's weekly newsletter, al-Naba.

"On Tuesday, 11 Safar, one of the soldiers of the Islamic State attacked a number of crusaders on a street in New York City, close to the monument for the 9/11 raid, which resulted in killing and wounding more than 60 crusaders, and unto Allah is all praise," the newsletter said in a translation by SITE Intelligence Group, a company that tracks extremist groups.

The "11 Safar" is a reference to the attack occurring in the second month of the Islamic calendar.

The newsletter calls Saipov "one of the soldiers of the Caliphate" and claims the attack inspired "fear in crusader America."

"The grace of Allah, the operation instilled fear in crusader America, prompting them to increase security measures and intensify actions against immigrants to America," the newsletter stated.

Saipov, NYPD police have said, shouted "Allahu Akbar" -- or "God is Greatest" in Arabic -- after intentionally driving a rented truck onto a bike and pedestrian path in lower Manhattan just after 3 p.m. on Tuesday and running down 20 people. The suspect also left a handwritten note in Arabic at the scene saying ISIS "would endure forever," according to authorities.

"He did this in the name of ISIS, and along with the other items recovered at the scene was some notes that further indicate that," said John Miller, NYPD deputy commissioner of intelligence and counterterrorism. "He appears to have followed almost exactly to a 'T' the instructions that ISIS has put out in its social media channels before with instructions to their followers on how to carry out such an attack."

Authorities also reported Saipov had ISIS propaganda, including about 90 videos, on his cell phone, which inspired him to carry out the deadly attack.

"The FBI stated there is no apparent tie to international terrorism," one senior official told ABC News. "Perhaps ISIS is just trying to take credit."