Tokai University, a four-time Japanese national university baseball champion, said Saturday it has suspended all activities of its baseball club indefinitely due to illegal drug use by several members.

According to the university, which has several campuses across the country, some members of the club based in Kanagawa Prefecture, near Tokyo, have admitted to the drug use at the team dormitory, saying they "used them out of curiosity."

In a press conference held Saturday, university officials said the Kanagawa prefectural police had raided the dormitory the same day, adding the university will cooperate fully with their investigation.

The university said it suspected that the members had used cannabis, but did not elaborate any further.