CHICAGO (CBS) — With both the nation, and the city, on high alert, police are taking no chances on potential terrorist threats.

Last night, there was a large police response on the Gold Coast, as officers were trying to figure out whether an incident was the real deal, a false alarm or a drunken joy ride.

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On Rush Street last night, SWAT teams descended with heavy weapons, after two people pulled up in a white van and yelled out that they were with ISIS.

The suspects were described as bearded men in a white van with temporary plates. When police tried to stop them, the van sped away.

Uniformed cops and SWAT teams buzzed the area but they never caught the suspects.

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Police now believe they were probably just joking around.

CBS 2 Security Consultant Ross Rice said: “It’s something common sense would tell you you can’t and shouldn’t do.

“You can’t make false threats. You can’t claim there’s a bomb on a plane. You can’t go up and down the street yelling you’re ISIS. It just doesn’t work.”

Today, SWAT teams hit the CTA Blue Line at LaSalle after reports of a suspicious person of “Middle Eastern descent who kept looking around suspiciously,” according to police dispatch reports.

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Despite the response, police later said the report was unfounded.