Police sources told New York ABC station WABC that officers reported to a street corner in the Bedford-Stuyvesant neighborhood of Brooklyn after receiving multiple calls for bad reactions to the drug. The sources said at least 25 people were taken to the hospital to be treated for adverse symptoms.
Officials told WABC none of the patients are in life-threatening condition.
The drug, often labeled synthetic marijuana, doesn't include any actual cannabis.
Synthetic weed, also called K2 or spice, is dried plant material sprayed with chemicals, which can be smoked or sold in liquid-form to be inhaled with a vaporizer. According to the National Institute on Drug Abuse, effects can be "unpredictable and, in some cases, more dangerous or even life-threatening."
The overdoses on Saturday occurred at the intersection of Broadway and Myrtle Avenue under the J, Z subway tracks. The location is well-known by authorities.
In July 2016, at least 33 people had serious adverse reactions to synthetic weed in one day at the exact same corner, and over 100 were taken to the emergency room from July 11 to July 13, 2016, according to the National Institute of Health.