Nigeria on Wednesday issued a travel ban on citizens from 13 countries worst-hit by coronavirus.

The announcement came as authorities confirmed five new virus cases, bringing to eight the number so far tested positive in Africa's most populous nation of 200 million people.

The government said on Twitter it "is restricting entry into the country for travellers from... China, Italy, Iran, South Korea, Spain, Japan, France, Germany, Norway, US, the United Kingdom, Netherlands and Switzerland.

"These are all countries with over 1,000 cases domestically."

Nigeria said issuance of visas would be suspended to nationals of these nations, and Nigerians arriving from these countries would be quarantined for 14 days.

It also advised Nigerians to avoid travelling to the affected countries.

It said the restrictions would come into effect from Saturday and could be reviewed after a month.

The announced further measures to bolster the country's economy, which is heavily dependent on oil exports, as the price of oil plummeted over fears the virus could lead to a .

Nigeria has also banned from travelling out of the country until further notice.

The government has suspended a major national sport event, advised against public gatherings and stressed the need for public hygiene to reduce the risk of spreading the disease.

The Central Bank of Nigeria (CBN) had already approved a $135-million fund to support businesses hit by impacts of the virus.

In addition, the bank said it would give double that amount to the country's health authorities, "to ensure laboratories, researchers and innovators work with global scientists to patent and or produce vaccines and test kits in Nigeria."

"Given the continuing impact of the disease on global supply chains," the bank said, it would also release one trillion naira ($2.7 billion) to help boost "all critical sectors of the economy".

The petroleum ministry said President Muhammadu Buhari had approved reducing prices at petrol pumps.

© 2020 AFP