The Nigerian government has reintroduced stricter lockdown conditions amid concerns about the fragility of the country's health system and disruption of vaccine deliveries.

Face masks are now mandatory in all government buildings, bars and night clubs will remain closed, and public gatherings restricted to 50 people.

The restrictions come into effect on Tuesday.

Most countries in Africa - including Nigeria - have experienced a second wave of the pandemic, with some seeing a third wave due to new more contagious variants.