MONTREAL (REUTERS) - A further two cases of the Omicron coronavirus variant have been detected in Ottawa, bringing Canada's total number of cases to five, Ottawa Public Health said late on Monday (Nov 29).

Earlier in the day, Quebec discovered its first Covid-19 case of the variant, health officials said.

Quebec Health Minister Christian Dube also told reporters that 115 travellers coming from countries impacted by the new variant, primarily South Africa, were called and asked to isolate and test for Covid-19.

Quebec's first case was a recent traveller to Nigeria, public health director Horacio Arruda said, similar to the two cases reported on Sunday by Ontario province.

The arrival of the new variant ahead of the Christmas holiday season comes as Quebec faces a recent hike in cases, mostly in the unvaccinated, Mr Dube said. In the last 24 hours, Quebec has reported 756 new cases.

Mr Dube urged travellers to rethink holiday trips and warned against large celebrations. The province limits gatherings in private homes to 10 people.

"The next few weeks will be critical," Mr Dube said.

Ontario said on Monday it had not detected any more cases of Omicron. But chief medical officer Kieran Moore told reporters that "in an abundance of caution... we really do need enhanced testing of returning travellers".

"We're pushing that from the government of Ontario's perspective," he added.