Nigeria has placed a travel ban on people coming from 13 countries worst affected by the coronavirus outbreak as five new cases were recorded in Africa's most-populous nation.

That brings the country's total number of patients with Covid-19 to eight.

Health Minister Osagie Ehanire said contact tracing for the new cases was ongoing. All the five had travelled to the UK and/or the US.

The Nigeria Centre for Disease Control (NCDC) tweeted about the cases, urging Nigerians to remain calm:

@Fmohnigeria has announced 5 new cases of #COVID19 in Nigeria bringing the total number confirmed cases in Nigeria to 8

All 5 cases had a travel history to the UK/USA

We urge Nigerians to remain calm as public health response activities are intensified across the country pic.twitter.com/yoKLHXoxhq

— NCDC (@NCDCgov) March 18, 2020

Travellers from China, Italy, Iran, South Korea, Spain, Japan, France, Germany, the US, Norway, the UK, the Netherlands and Switzerland will not be able to come to the West African from Saturday 21 March.

Nigerians have also been advised to cancel or postpone all non-essential travel to these countries, which all have reported more than 1,000 cases.

The BBC's Chris Ewokor in the capital, Abuja, says Nigerians returning to the country must now self-isolate for 14 days.

On Tuesday, the government also placed an indefinite ban on all public officials from embarking on foreign trips, he says.