Four students from Wesleyan University in Middletown, Connecticut, were arrested Tuesday after several students were hospitalized over the weekend after taking a drug called Molly. The arrested students were taken into custody on assorted drug charges and were suspended from the university, The Associated Press reported.

Eric Lonergan, of Rio de Janeiro; Andrew Olson, of Atascadero, California; Zachary Kramer, of Bethesda, Maryland; and Rama Agha Al Kakib, of Lutherville, Maryland, were identified as those arrested. The four were jailed Tuesday and are due to be presented in court next Tuesday.

"This particular batch may have had a mixture of several kinds of designer drug chemicals, making the health risks unpredictable and treatment to combat the effects complex and problematic," Middletown police chief William McKenna said, according to the AP.

Lonergan is accused of possessing a controlled substance and illegally obtaining or supplying drugs while Olson currently faces charges of possessing and selling a hallucinogen. Kramer is accused of possessing a regulated substance and marijuana along with drug paraphernalia, while Al Kakib has been charged with the possession of a controlled substance, which he had planned to later sell.

The university became aware of the incident after several students sought treatment at a hospital near the campus while two students, who were in a critical condition, had to be airlifted to a hospital in Hartford, about 20 miles north of the campus, AP reported.

Police officials are investigating the incident to identify the suppliers of the drug, which was delivered during a rave music show, following which 10 Wesleyan students and two visitors had to be given medical assistance.

Police officers are searching for evidence in the case and have searched locations in and around Wesleyan's campus in Middletown, McKenna said, adding that various agencies are trying to identify the different chemicals in the batch of Molly that caused the overdose, according to the AP.

"Incidents jeopardizing the safety will not be tolerated," McKenna said, according to AP, adding: "and those offenders will be held accountable."

Molly is a refined form of Ecstasy, a drug also known as methylenedioxy-methamphetamine (MDMA). The drug can cause a user’s temperature to rise, and could lead to failure of the liver, kidney or cardiovascular organs.