CARLTON, Minn. (AP) -- Authorities say a suspicious device allegedly thrown by a protester at a construction site for the Enbridge Energy Line 3 replacement pipeline was not an explosive.

Nearby residents who had been evacuated were allowed to return to their homes by Friday evening.

Authorities began investigating Friday, and a bomb squad was called after a protester allegedly threw a device then drove away.

Workers and roughly 40 residences within a half-mile radius were evacuated and Enbridge shut down its pipelines in the area out of caution.

There were no immediate arrests, but state and federal authorities are still investigating.

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