NEW YORK (CBSNewYork) — The NYPD on Monday issued an alert that exceedingly dangerous K2 is still popping up around Brooklyn.

The department released photos of some of the packages, and say 49 people have overdosed since the first case on Friday.

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Police say they’ve traced the drugs back to five different sale points, but they’re still trying to determine where it originates from.

13 people have been arrested.

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