A Wesleyan University sophomore was reported as in critical condition along with 10 other students for overdoses of the drug MDMA, a school official said on Sunday.

According to Reuters, the sophomore was transported to a hospital early on Sunday with students who showed similar symptoms but were in less serious conditions, said Michael Whaley, vice president for student affairs.

In a letter to the school community, university President Mark Roth revealed eight of those affected on Sunday remained hospitalized on Monday, though four were expected to be released later in the day, The Associated Press noted.

Wesleyan spokeswoman Lauren Rubenstein said the students were admitted "with overdose symptoms consistent with the use of Molly," which is the street name for a drug that is pushed as the pure powder form of MDMA, an illegal . substance. MDMA is the main chemical in ecstasy, a psychoactive drug.

"If you are aware of people distributing these substances, please let someone know before more people are hurt," the university president said. "These drugs can be altered in ways that make them all the more toxic. Take a stand to protect your fellow students."

Police in Middletown, Connecticut, where the private liberal arts college has been based since 1831, said they are looking into information about a "bad batch" of the drug.

"Our first and foremost goal is to obtain information on the batch of Molly that was distributed to the students on the campus," Chief William McKenna said. "This information is critical in ensuring the recovery of those students affected."

McKenna asked the students to check on their friends to make sure they were doing well and to contact the director of public safety if they had information about the incident, NBC News noted.

Molly has become an increasingly common concern for concert promoters, campus police and local officials.

"I think Molly is becoming a really big thing nationally and everyone is thinking, 'Oh, it's safe,'" said Zaida Garcia, a Wesleyan senior. "And everyone is doing it, and there could be other stuff in there."