Two University of Colorado students have been arrested for allegedly feeding marijuana-laced brownies to their unsuspecting classmates and professor, police said.

Thomas Ricardo Cunningham, 21, and Mary Elizabeth Essa, 19, baked the pot-laced brownies for the class as part of a "bring food day," the University of Colorado Police Department said in a news release on Sunday. The professor and classmates were unaware that the brownies contained tetrahydrocannabinol or THC, the active ingredient in marijuana, police said.

On Friday morning, officers were called to the Hellems Arts and Sciences Building on the Boulder campus on a report of a professor who was complaining of dizziness and going in and out of consciousness.Paramedics transported her to a hospital.

Later that afternoon, a student's mother notified campus police that her daughter, who had been in the professor's class, was having an anxiety attack and was at a hospital. On Saturday, a second student told police that she felt like she was going to "black out" after the class. Her family took her to the hospital for evaluation.

An investigation revealed that the three hospitalized victims - and five other classmates - were suffering from the effects of marijuana, police said. The three hospitalized victims have since been released.

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Cunningham and Essa were interviewed by police on Saturday evening and admitted that the brownies contained marijuana, police said.

They were arrested on suspicion of four felonies: second-degree assault, inducing consumption of controlled substances by fraudulent means, conspiracy to commit second-degree assault and conspiracy to commit inducing consumption of controlled substances by fraudulent means.

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SAN DIEGO -- San Diego police are investigating whether three Metropolitan Transit System bus drivers were under the influence of marijuana-laced brownies during their routes, officials say.

Metropolitan Transit System spokesmanRob Schupp said three drivers became sickened and reported feeling “dizzy” Sunday while on their routes, possibly after eating pot-laced brownies handed out by another employee.

Previous reports incorrectly said four drivers were sickened.

Transit officials say the three bus drivers acted appropriately by pulling off the road once they realized they had become ill. Replacement drivers were called in, according to NBCSanDiego.com.

It was not known if passengers were on board, or for how long the bus operators were driving while feeling ill, according to NBCSanDiego.com.

View NBCSanDiego.com's story on the bus investigation

According to transit system officials, drug tests were administered to the employees who reported feeling sick. The allegation of the drivers eating the drug-laced brownies, however, has not been confirmed by San Diego police, according to NBCSanDiego.com.

All three, plus an additional employee who allegedly distributed the suspected baked goods, were placed on paid leave while authorities conduct an internal investigation.

Metro Transportation System chief Paul Jablonski says the drivers followed procedures to the letter and supervisors acted quickly to protect the public, according to The Associated Press.

Metro officials say they have a comprehensive drug and alcohol policy that tests all new employees and conducts random tests throughout the year. The program exceeds guidelines set forth by the Department of Transportation, according to NBCLosAngeles.

NBCSanDiego.com's Lauren Steussy and Monica Garske contributed to this story.

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