By Bill Shields

BOSTON (CBS) — After ISIS produced a video containing veiled threats against New York City, Boston is on heightened alert.

“In the wake of the Paris attacks, we should be on alert,” says Mayor Marty Walsh.

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He adds that there is no credible threat against Boston, but ever since 9-11, the city has trained its first responders for a terrorist attack, even chemical.

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“We train frequently for chemical and biological attacks, and I feel we are prepared,”  Boston Police commissioner William Evans said.

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“I feel confident and comfortable, but we’re on alert,” Walsh said.

Bill Shields