Doctors in Nigeria's Cross River state began an indefinite strike on Monday in protest over allegations the authorities were whitewashing coronavirus cases in the region.
According to figures by the Nigeria Centre for Disease Control (NCDC), southern Cross River is the only state in the country where no case of COVID-19 has been officially confirmed.
But the regional branch of the Nigeria Medical Association (NMA), the main doctor's union, said positive cases were recorded at a government-run hospital in state capital Calabar last week.
"The association demands explanation from NCDC, why the five COVID-19 confirmed cases from UCTH (teaching hospital) carried out at the NCDC accredited Molecular Laboratory...have not reflected in the daily situation report of NCDC," since July 1, it said.
The union said the lives of its members, as frontline workers in the battle against the virus, were being put at great risks by the situation.
"The Cross River State government has abdicated her responsibility of contact tracing, treatment and care for the five confirmed cases," it said.
The doctors body said its members would be on "an indefinite strike" until the local government and NCDC acceeded to its demands.
State government spokesman Christian Ata told AFP the strike was "ill-advised and based on a wrong premise".
He said the government had taken precautionary and preventive measures to stop the spread of the virus into the state.
State health commissioner Betta Edu urged the doctors to suspend their action in the interests of the people.
"So you go on strike because NCDC refused to upload results? This is killing the same people the doctors seek to protect. This is bad."
Edu said the state government had requested details of the five cases and insisted the authorities would respond.
Nigeria has so far reported 28,711 infections and 645 deaths since the first index case of the virus in late February.
More than 800 medics have contracted the disease, according to the NCDC.
Doctors in the country have launched or threatened a series of strikes during the pandemic over issues ranging from lack of protective equipment to harassment by security forces.