ISIS recently called for the type of attack that just happened at Ohio State

The terrorist group ISIS had called in recent months for knife and vehicle attacks of the sort that a Somali immigrant carried out at Ohio State University on Monday.

The attacker drove into a group of pedestrians with a vehicle on OSU's campus before using a butcher knife to stab people. Eleven people were sent to the hospital with injuries. A campus police officer killed the attacker at the scene.

ISIS claimed credit for the attack on Tuesday, and supporters of the group were spreading information about it through online channels shortly after it happened. And the specific motive behind the attack is unclear - the attacker, 18-year-old Abdul Razak Ali Artan, had cited Al Qaeda cleric Anwar al-Awlaki on his apparent Facebook page.

While it's still unclear whether any one group inspired the attack, terrorism analysts have been quick to note that it closely mirrored recent ISIS propaganda.

Michael S. Smith, the founder of security firm Kronos Advisory who has also advised Congress on terror-related issues, pointed out on Twitter that an ISIS video released days before the OSU attack showed a French ISIS member demonstrating how to kill people using knives. He also called for ISIS attacks in the West.

And in the past two months, English-language ISIS propaganda magazines have called for vehicle and knife attacks.

The latest issue of Rumiyah, a new magazine from the terror group aimed at English-speaking populations, included an article titled "Just Terror Tactics," which outlined ideal vehicles to use in terror attacks as well as ideal targets.

"Though being an essential part of modern life, very few actually comprehend the deadly and destructive capability of the motor vehicle and its capacity of reaping large numbers of casualties if used in a premeditated manner," the article said.

The article also cited the attack in Nice, France, from earlier this year in which a supposed ISIS supporter killed 86 people by plowing into a crowd with a truck on Bastille day.

"Vehicles are like knives, as they are extremely easy to acquire," the article said.

The previous issue of Rumiyah included another "Just Terror Tactics" article that provided tips for knife attacks.

Knives "are widely available in every land and thus readily accessible," the article said. "They are extremely easy to conceal and highly lethal, especially in the hands of someone who knows how to use them effectively."

The article also described how to choose a knife and target.

ISIS spokesman Abu Mohammad al-Adnani, who is now deceased, has also called for these attacks. He said in 2014: "If you are not able to find an IED or a bullet, then single out the disbelieving American, Frenchman, or any of their allies. 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."

Adnani issued a similar directive again in 2015.

And even if Artan wasn't directly inspired by ISIS, it's likely the group will still use the attack to push its message.

"Even when there is no linkage to the group, it is common for [ISIS] supporters to promote information about these types of events in the West," Smith said on Twitter. "This can help stimulate thinking about opportunities to execute attacks among 'fence sitters' in the US whom the group is using social media as a tool to help engineer and resort to violence."

In addition to referencing an Al Qaeda cleric in his Facebook posts, Artan implored Americans to make peace with "dawla in al-sham," which appears to be a reference to the self-declared Islamic emirate ISIS has established in Syria.

Strategic security firm The Soufan Group also noted the similarities between ISIS propaganda and this latest attack.

"If Artan's motivation is determined to be terrorism, investigators will first look for any accomplices," a Tuesday note from the firm stated. "Authorities will then look for evidence of any direct communication Artan may have had with known extremists, or if he was simply motivated and inspired through extremist propaganda."

Some analysts warned against jumping too conclusions too early on.

ISIS "doesn't maintain a monopoly over global jihad," Naval War College researcher Nicholas A. Galvin wrote on Twitter. "Yesterday's initial assumptions were dangerous."

He continued: "It's a very 2015 mentality to assume an attack in West is perpetrated by IS. Artan's background & campus interview hint at his grievances."

Galvin appears to be referencing a recent profile of Artan in the school newspaper's "Humans of Ohio State" feature. Artan told the paper that he had just transferred from Columbus State Community College, and that as a practicing Muslim he "wanted to pray in the open, but I was kind of scared with everything going on in the media."

Natasha Bertrand contributed to this report.