MINNEAPOLIS (AP) -- Authorities say handguns and rifles that have been modified into fully automatic weapons that can fire up to 1,200 rounds per minute have been involved in a string of Minneapolis shootings and have been showing up at more crime scenes.

Police data show the city's ShotSpotter network has recorded 78 automatic gunfire activations of 935 total rounds, compared with five such activations of 42 rounds at this time last year.

It's not clear how many converted weapons are on city streets, but authorities say they have been tracking incidents involving them.

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