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AUSTIN (AP) — Investigators say emergency responders in downtown Austin have treated more than 50 people who got sick after allegedly using synthetic marijuana.

Austin police on Thursday detained three people, pending formal charges, as part of the investigation into the overdoses of so-called K2. Lt. Kurt Thomas says he expects drug possession or distribution counts to be filed.

Austin-Travis County Emergency Medical Services on Wednesday began responding to reports of mainly homeless people suffering adverse reactions to K2. The agency, through late Thursday, reported 45 incidents involving 52 patients being treated, including some transported to hospitals.

Some victims were found unconscious or having seizures.

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