Africa's largest city Lagos could return to lockdown to halt the coronavirus if residents continue to ignore social distancing rules, the governor warned Saturday. 

Nigeria's economic hub emerged on Monday from a five-week stay at home order that left the city's large number of poor struggling to make ends meet. 

But since the easing of the restrictions people have been seen thronging markets and banks despite orders remaining in place to avoid mass gatherings.  

"It is disappointing to see the crowd at banks and markets across the state flouting the guidelines," Lagos governor Babajide Sanwo-Olu wrote on Twitter.

"We will be forced to take the painful decision of bringing the state under lockdown if it remains clear that Lagosians are determined to flout the rules."

Nigeria, Africa's most populous nation, has confirmed 3,912 infections and 117 deaths from the novel coronavirus. 

Lagos, a city of some 20 million people, has been the country's main hotspot and the daily increase in recorded cases has doubled in the past few days.

Sanwo-Olu said that Lagos state would change its "isolation strategy" and that district healthcare facilities would handle "mild-to-moderate" cases. 

Half of Nigeria's 200 million population live in dire poverty, making it a major challenge to impose lockdowns cutting them off from daily earnings. 

Measures introduced in place of the total lockdown include a night-time curfew and the mandatory wearing of masks in public.