The World Health Organization will meet on Friday to assess a new variant detected in South Africa that is feared to be the worst Covid-19 variant yet identified.

More countries are tightening their travel restrictions after the discovery of a new coronavirus variant in South Africa earlier this week.

The UK, Singapore and Japan are among those rushing in stricter quarantine measures and banning flights from South Africa and neighbouring countries.

The EU is proposing to ban flights from the region across the whole bloc.

Scientists still have much to learn about the variant, but there are concerns it may be the worst yet.

It is still so new to scientists, they are yet to give it a more memorable name, like Delta or Beta. Right now, it is known as B.1.1.529, but the World Health Organization (WHO) is expected to name it on Friday.

It is very different to the other variants discovered so far, and is the most heavily mutated version, which means vaccines, which were designed using the original strain from Wuhan, may not be as effective.

The WHO says so far under 100 samples have been sequenced. Cases have mainly been confirmed in South Africa, but have also been detected in Hong Kong, Israel and Botswana.

Only about 24% of South Africa's population is fully vaccinated, which could see a rapid spread of cases there, Dr Mike Tildesley, a member of the Scientific Pandemic Influenza Modelling group (Spi-M) told the BBC on Friday.

Israel's PM Naftali Bennett said on Friday it is "on the verge of a state of emergency" regarding the new variant, and that he would "act fast, strong and now".

One case was detected in a person who returned from Malawi, according to Israeli media reports quoting the country's health ministry. Another two suspected infections were yet to be confirmed with test results. All three are said to have been fully vaccinated.

The UK and the Netherlands have halted flights from these southern African nations:

South Africa

Botswana

Namibia

Zimbabwe

Eswatini (formerly Swaziland)

Lesotho

Singapore, Italy and Israel have placed all of those nations, plus Mozambique on their red list.