TULSA, Oklahoma - Police said a spike in synthetic marijuana usage led to at least 20 people passing out and three arrested in Tulsa Tuesday.

Nine of those patients collapsed downtown, outside of the Iron Gate Soup Kitchen.

Police said they've arrested 29-year-old Bamf Hunter, believed to be the dealer, for possession with intent to distribute. Also arrested was Thomas Colishaw, 21, for possession, public intoxication and larceny.

Late Tuesday, police served a warrant at the Phillips 66 convenience store at 5425 East 11th Street where officers said the two men bought the K2. They say 47-year-old Abdur Rahim who works at the store and was also arrested.

EMSA took most of the those affected were taken to Tulsa hospitals with what police called one of the most toxic forms of synthetic marijuana.

During a search of the gas station, police said they seized a massive amount of synthetic substance and believe their investigation links the store with the drugs distributed in downtown Tulsa.

Tuesday, Alvin Guess watched as people he knew - some of them his friends - succumbed to the synthetic marijuana.

"I know a lot of these guys, they're just hooked on that K2. It's just a bad batch that came out today," he said.

Police officers said they took one man into custody, whom they believe could have supplied that bad batch.

They found him along Katy Trail just west of the Tulsa County Jail. They said he had 15 to 20 grams of what they call “Pink Bubble Gum” - one of the most toxic forms of K2, on his person.

Kelli Bruer with EMSA said, "We don't know when it'll stop. We don't know the substance or the product that's out there that's causing it, and how much of it's out there."

EMSA said at least 20 people were treated for their symptoms - unconsciousness and convulsions. Two of them are as young as 12 and 16.

Most of the patients were found in the downtown area - many of them homeless.

Two men found on Katy Trail were seizing and unresponsive when emergency crews first showed up.

"Unconscious, unresponsive, incoherent to the point they're falling down, can't speak, seizure-like activity, seizing of the body on the ground," Bruer said.

EMSA said it's too early to say for sure if all of the cases are related, but it's clear the patients were all smoking some kind of synthetic substance.

"All you can do is just pray for them," Guess said.

Police have not yet arrested the suspect from Katy Trail, as they're still waiting for lab results on the substance to come back.

They said the man was handing out the substance to people for free.

Late Tuesday night, crews responded to what they believe was another overdose of synthetic marijuana at the Tulsa Transit terminal.

Police said one person was vomiting and unresponsive to medical crews when the first arrived.

Bruer said, while they can’t confirm the calls are related, she said, “due to volume and geographical area, we believe that more than 15 or more calls are related to the same cause.”

Police said they suspect there are more dealers, but they believe Hunter is the main suspect.