ST. LOUIS • Dozens of people have been treated downtown over the past several days after apparently overdosing on a synthetic cannabis-like drug, officials said Wednesday.

“People were standing and walking around like zombies,” said St. Louis Fire Chief Dennis Jenkerson. “They didn’t know what they were doing or where they were at.”

Some were found lying in the streets and on sidewalks.

Most of those overdosing appeared to be homeless, Jenkerson said, and most were in the area of New Life Evangelistic Center on Locust Street or the nearby Central Library branch. Jenkerson said 18 were treated in those areas Monday, eight Tuesday and more Wednesday. Many of them were taken to a hospital.

About 11 a.m. Wednesday, Jenkerson said, “the police chief was passing by the north side of the library when he saw seven people down, and by the time the fire department arrived, there were 11 down within a 20-minute period.”

When paramedics arrived on the scene, there were men and women lying on the ground, Jenkerson said. Some were having seizures, moaning and asking for help. On Monday, Jenkerson said, people were taking off their clothes.