Twenty-two Grade 8 students and three adults from the Toronto-area were treated by paramedics after they suddenly fell ill and started vomiting while on a school trip to Ottawa.

Paramedics were called to the Quality Inn on Rideau Street in downtown Ottawa to treat the students for their symptoms Friday morning.

"They are responding well to the treatment right now," said J.P. Trottier with Ottawa Paramedic Service. "Nausea, vomiting, diarrhea were the symptoms . . . three or so were treated with IV, as well as Gravol."

Although initial reports said the illness may be related to food poisoning, others in the group ate at the same restaurant and did not get sick.

Public health authorities say the students, who go to Father Frederick McGinn Catholic Elementary School in Richmond Hill, may have caught a virus.

"From our experience it does appear to be a norovirus type of thing," said Siobahn Kearns with Ottawa Public Health. "It's one of the heartiest viruses, a 12 to 24 hour period of incubation from the time of first exposure."

One student apparently reported feeling unwell when the group travelled to Ottawa.

Parents were notified and none of the students were sent to hospital. Two buses will take the students home Friday night; one with students showing symptoms and one for those appearing healthy.

The York District Catholic School Board said the bus that took the students to Ottawa is not being used.

This time of year is the most popular time for students to take part in school trips to the capital.

With a report from CTV Ottawa's Karen Soloman