(CNN)Africa's most populous nation is on high alert as three people in the country have the newly identified coronavirus variant Omicron, a statement from the Nigeria Center for Disease Control (NCDC) confirmed.
Nigeria on high alert as it confirms three cases of Omicron variant
The test results "were positive for this variant in three persons with history of travel to South Africa. These cases were recent arrivals in the country in the past week," the statement said.
"The NCDC assumes Omicron is widespread globally given the increasing number of countries reporting this variant. Therefore, it is a matter of when, not if, we will identify more cases."
Nigeria's travel advisory has been updated and now requires travelers to the country to pre-book a day 2 and day 7 PCR test and present a negative COVID-19 test result, which must be done two days before departure.
"Pre-booking and payment for all day 2 and day 7 COVID-19 PCR tests are prerequisites for travel," the new travel requirement states.
These are the first known cases of the Omicron variant in Nigeria, the statement said.
Canada also added Nigeria to a list of countries with entry prohibitions, other countries added include Egypt and Malawi.
Foreign nationals who have been in any of these nations within the previous 14 days were barred from entry to Canada, according to the new border measures, which are in addition to the southern African countries already on the prohibited list.
Five cases of the variant confirmed in Canada had travel history from Nigeria, Canadian health officials said.
Indonesia had earlier banned the arrival of foreigners who have visited Nigeria, South Africa, Botswana, Namibia, Zimbabwe, Lesotho, Mozambique and Eswatini within the last 14 days, while requiring a compulsory 14-day quarantine for citizens who had spent time in those countries.