Spanish government announced Tuesday that it would restrict arrivals from Brazil and South Africa by air to try to reduce the spread of COVID-19 news strains.

Only legal residents or nationals of Spain and the neighboring microstate of Andorra will be allowed in from Brazil and South Africa, government spokeswoman Maria Jesus Montero told a news conference.

Passengers stopping in Spain while on their way to another country will be allowed to enter as long as they will remain for less than 24 hours and do not leave the airport, she added.

The new rules will take effect on Wednesday and will remain in force for two weeks although it could be extended depending how the pandemic evolves, the minister said.

Madrid has since the end of December banned arrivals by sea and air from Britain except for residents or nationals of Spain and Andorra because of the discovery of a new more contagious virus strain there last year.

This strain, which has led to a surge in infections in Britain in recent months, is one of several virus variants have been identified since the genesis of the pandemic last year.

Another strain, known as E484K, detected initially in South Africa and on subsequent variants in Brazil and Japan, has raised greater alarm among researchers over its possible impact on immunity.

Spain has been hard-hit by the pandemic, recording nearly 60,000 deaths from over 2.8 million cases so far, including 350 of the strain detected in Britain.