“Be particularly careful” if you intend to visit the Mall of America.

That’s the cautionary message Sunday from Jeh Johnson, the U.S. secretary of Homeland Security, in the wake of Somali terrorist group Al-Shabab releasing a video calling for attacks on Western malls. The video specifically mentioned the megamall in Bloomington.

“If anyone is planning to go to the Mall of America today, they’ve got to be particularly careful,” Johnson said in a televised interview with CNN. “There will be enhanced security there, but public vigilance, public awareness and public caution in situations like this is particularly important, and it’s the environment we’re in, frankly.”

In following up to Johnson’s message to Mall of American visitors, another department official wanted to make clear that the secretary was not urging people to stay away from the mall.

“Secretary Johnson didn’t say that they should not go to the mall,” assistant secretary Tanya Bradsher told CNN. “He told shoppers to be extra vigilant and that security was increased.”

In a second Sunday morning news show interview, on ABC-TV, Johnson said the threat against the Mall of America represents a “new phase [in] terms of the global terrorism threat ... that is more complex, more decentralized, more diffused. ... The reason I think we’re all concerned about this is because it encourages strike with very little notice to our intelligence community, our law enforcement community here at home.”

Shoppers at the Mall of America in November.

Johnson said he has been visiting Minneapolis and other major metropolitan areas and “meeting with community leaders, talking about the importance of public participation in our efforts.”

The Mall of America upped security Saturday after Al-Shabab’s video was released. A security employee read a statement saying the mall was aware of a video that mentions and shows images of the Bloomington megamall, and that it has “implemented extra security precautions.”

“Some may be noticeable to guests and others won’t be,” it said. “We will continue to follow the situation along with federal, state and local law enforcement and will remain vigilant as we always do in similar situations.”

A mall spokesman declined further comment.

The video, circulating on Twitter, is more than an hour long and focused on the September 2013 attack on the Westgate Shopping Mall in Nairobi, Kenya. At least 67 people died in that siege.

At the end of the video, a masked man says: “If just a handful of mujahedeen fighters could bring Kenya to a complete standstill for nearly a week, then imagine what the dedicated mujahedeen in the West could do to American — or Jewish-owned shopping centers across the world? What if such an attack were to occur in the Mall of America in Minnesota? Or the West Edmonton Mall in Canada? Or in London’s Oxford Street?”

The man then urges fighters to “hurry up.”

On Friday, Al-Shabab militants attacked a popular hotel in Mogadishu with a car bomb and suicide bomber, killing at least 25 people.