Doctors at state-run hospitals in Nigeria have embarked on an indefinite strike over pay, inadequate facilities and lack of protective equipment.
They are also demanding the payment of a hazard allowance during the coronavirus pandemic.
The strike was called by the National Association of Resident Doctors (Nard), which represents about 40% of Nigeria’s doctors.
Many hospitals lack basic necessities such as beds and medicine.
The authorities say the strike will hamper efforts to deal with the pandemic, including a programme to administer 40 million doses of the Oxford-AstraZeneca vaccine, although this was denied by Nard.
According to the union, 17 doctors have died of Covid since the first case was diagnosed in Nigeria in March 2020.
The group says they initially received a monthly hazard allowance of $12 (£9), but that those payments stopped after three months.
Since the start of the pandemic, Nigeria has registered over 160,000 cases of Covid-19 and 2,000 deaths.