Nigeria's 12 recently-reported cases of coronavirus are Nigerians who came into the country through Benin Republic.
While speaking during a media briefing on Wednesday, April 1, 2020, the Minister of Health, Osagie Ehanire, said they were discovered when a bus of over 100 Nigerian passengers were intercepted.
He said they were headed for Osun State.
"They said they were coming from Ivory Coast or Ghana, I'm not quite sure.
"It's among those groups that we have 12 immediate new entrances, so those are imported cases," he said.
The Nigeria Centre for Disease Control (NCDC) announced earlier on Wednesday that 12 new cases were recorded in Osun (9), Edo (2), and Ekiti (1).
Nigeria has already banned international flights into the country and locked its land borders.
Travellers came from Ivory Coast - Osun government
In a statement released after the minister's media briefing, the Osun State government said the travellers came into the country from Ivory Coast on Saturday, March 28.
Ismail Omipidan, the chief press secretary to Osun's Governor Gboyega Oyetola, said the group of 127 travellers were immediately isolated in Ejigbo without coming into contact with the general public.
"Between Saturday and Tuesday, 24 samples of the returnees were sent for COVID-19 testing and three of the samples came back positive.
"Another 47 samples were sent for testing again and the result came back today (yesterday) with nine more persons testing positive.
"The results of the remaining 56 persons are being expected, but at this point, we will be needing the assistance of the Federal Government to manage those that have tested positive and others that may still test positive," he said.
The state government has already ordered a shutdown of social and economic activities for a period of two weeks starting from March 31.
Nigerians won't be denied entry - Ehanire
Despite the closure of land borders, Ehanire said the new cases had to be let into the country because they are Nigerians and couldn't be denied.
However, the minister urged Nigerians abroad to stay where they are unless it's absolutely important to travel.
"The travellers put themselves at risk, so my advise is stay where you are and not take the risk. Unless you're walking," he said.
Nigeria has recorded a total of 151 coronavirus cases, as of April 1, in 12 states across the country. Nine people have recovered and been discharged, while two people with underlying illnesses have died as a result of coronavirus infection.