Osun state has recorded six new cases of coronavirus, bringing the number of infections in the state to 20.
Commissioner for Health, Rafiu Isamotu, announced this on Thursday.
All the 127 Ivory Coast returnees had been tested and 18 of them had returned positive, Isamotu said.
The Nigerian Center for Disease Control (NCDC) had on Wednesday announced that nine of the returnees who came into the country by land tested positive for the disease.
Osun governor, Gboyega Oyetola, had ordered the closure of borders with neighbouring states and imposed a lockdown so as to retard the spread of the disease.
He also signed the Diseases (Emergency Prevention) Regulations, law 2020.
The governor said the law is aimed at preventing and containing the spread of Covid- 19 anywhere within Osun.
Under the law, anybody who violates the order will be sentenced to six-month imprisonment or an option of fine upon conviction.
Transmission or dissemination of false information regarding Covid-19 is also an offence and attracts the same punishment.