SACKVILLE, N.B. — Classes were set to resume Monday at a New Brunswick university plagued for days by an unknown virus, but students who were ill were asked to stay home.

Mount Allison University in Sackville has been dealing with a suspected Norwalk-type virus that's made more than 300 people on and off the small campus violently ill.

Symptoms include diarrhea, vomiting and dehydration, and can last for up to 48 hours.

The outbreak prompted administrators to cancel classes on Friday and close much of the university over the weekend.

A university spokesman said the majority of sick students fell sick on Wednesday and Thursday, and it's believed the worst is over on campus.

"Courses can go ahead," Stephen McClatchie said Sunday. "But we still want to be vigilant. We want to avoid spreading this suspected virus any more."

About 45 more people reported falling ill on Saturday, though McClatchie said the number of infections was lower than on previous days.

Students who are recuperating won't be required to submit sick notes if they skipped class, and the university has asked professors to be lenient with late assignments.

Extra-curricular activities slated for Monday were to be rescheduled. Public buildings, including a fitness centre and art gallery, were also to remain closed.

Exams set for Monday or Tuesday will be rescheduled.

"We'll take it day by day," said McClatchie. "For the short term, we want our students to get healthy."

McClatchie said public-health officials expected to know Monday what kind of virus has hit the university.

Officials have said the virus bears the traits of Norwalk, a gastrointestinal virus that's spread through fecal-oral contact.

Norwalk can also cause nausea, abdominal pain, headaches, fatigue and occasional fever.

McClatchie said initial test results have ruled out that a bacterial pathogen, such as E.coli, has struck the university.

John Sheridan, a fourth-year student, thought he was suffering from food poisoning.

"My stomach felt like it was on fire, it was just instant pain," said Sheridan, who had visited his sister at a university residence earlier in the day.

"I started to vomit. Laying down was pretty painful, so I just sat on the couch all night and was awake, and went back and forth to the bathroom."

Sheridan said his vomiting lasted about seven hours, though he felt feverish and weak, and had stomach cramps for the rest of the day.

The biology student rested at home for a few days, though a number of students sought treatment for dehydration at a local hospital. None were admitted.

A team of janitors spent the weekend disinfecting bacteria-prone surfaces, such as computers and bathroom fixtures.

Students spritzed their hands with sanitizer before eating at the cafeteria.

And instead of grabbing a drink at the student pub, which was closed, students quashed their thirst with a rehydration drink made from water, sugar, and baking soda.

The president of the university's student council said she was pleased with the school's quick reaction to the outbreak.

"They've tried to keep on top of things as much as possible", said Erica Hendry, who lives off campus and managed to avoid the virus.

"I'm very grateful for what they've been doing."