A Canberra man has faced court charged with assaulting four people with a baseball bat in an Australian National University (ANU) classroom yesterday.

Alex Ophel, 18, sat quietly in a blue police jumpsuit for the duration of the ACT Magistrates Court hearing this morning.

Police allege Ophel entered a tutorial classroom at the ANU campus on Friday morning with a black duffel bag.

In court documents, police claim after a short time Ophel stood up with a baseball bat and began yelling incoherently and swinging the weapon.

The documents contain descriptions of Ophel using "maximum force" as he allegedly struck his lecturer and several students who tried to intervene.

The lecturer, along with three students were hospitalised — two have since been released.

Several victims sustained head injuries.

Ophel was arrested at the scene by police and has been charged with several counts of assault and inflicting grievous bodily harm.

The court today ordered he undergo a mental health assessment.

"The application was for an assessment ... that is to look specifically at his mental health, that's all we can say at the moment," Ophel's lawyer Tim Sharman said.

No date was set for when Ophel will reappear in court.