MINNEAPOLIS (AP) -  Minneapolis police spent more than two hours Friday searching a downtown office building after a report of possible shots fired, but said they found no evidence of a shooting.

Workers in the building were told to shelter in place during the search. The 11-story building includes some offices of Target Corp.

Acting Chief Janee Harteau said an initial caller heard a popping sound. Police speculated it might have come from ductwork.

The building search came less than two months after a gunman fatally shot six people at a Minneapolis business after he was fired.

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