Malawi will close its borders for 14 days and restrict public gatherings to 100 people following a new surge in cases of the coronavirus, the southern African nation's presidential task force on Covid-19 said on Tuesday.

After nearly two months without new positive cases, Malawi on Tuesday recorded 46 new infections, bringing the total number of infections to 6,248, with 187 deaths, according to the health ministry.

Malawi's borders and airports re-opened in October as positive cases fell, although some experts fear the real figure may be higher as just over 80,000 tests have been conducted.

Malawi has a population of around 19 million.

Though small in size - about one-tenth the size of South Africa - Malawi is among the top 10 in the continent in terms of population density, making it vulnerable to the fast-spreading respiratory disease.

The task force said in a briefing in the administrative capital Lilongwe that only essential services personnel and traffic carrying essentials like fuel and medicines would be allowed through the borders.

It said Malawians deported from other countries would also be allowed to enter the country. Those returning would be required to go into mandatory isolation facilities at airports, the officials said.

Labour minister Ken Kandodo tested positive for Covid-19 this week and had been admitted to hospital, where he reported to be in stable condition.