Six cases of the more contagious variant of Covid-19 first identified in the UK have been confirmed in India.

The six individuals who returned from the UK are being kept in isolation, officials said on Tuesday.

India joined a list of other countries last week in suspending flights to and from the UK.

The new variant is considerably more transmissible than previous strains but not necessarily any more dangerous, experts say.

With more than 10 million confirmed cases so far, India has the second-highest caseload in the world after the US.

The new strain can "cause havoc" and "throw our healthcare system out of control," Dr A Fathahudeen, a critical care expert who has treated hundreds of Covid-19 patients, told the BBC earlier.

Officials in India have begun contact-tracing close contacts and family members of the six who have tested positive for the new variant.

Passengers arriving from the UK will undergo RT-PCR tests at all airports in the country, an official statement said. The samples found to be positive will then be genome sequenced by government-run labs in order to detect the new variant.

Around 33,000 passengers arrived in India from the UK over the past month. Of those, 114 were found to be positive for coronavirus - their samples have been sent to ten labs for genome sequencing, according to the statement.

News of the new variant triggered travel restrictions around the world last week. Several countries such as Canada, Japan, Spain, Sweden and France have all confirmed the presence of the new strain.

In the UK, health officials have warned that the country's "very high" Covid infection level is a "growing concern". On Monday, a record 41,385 Covid cases and 357 deaths were reported in the UK.
What is the new variant?

The new variant first detected in southern England in September is blamed for sharp rises in levels of positive tests in recent weeks in London, south-east England and the east of England.

About two-thirds of people testing positive in these areas could have the new variant - but this is only an estimate, the Office for National Statistics (ONS) says.

Three things are coming together that mean the new variant is attracting attention:

It is rapidly replacing other versions of the virus
It has mutations that affect part of the virus likely to be important
Some of those mutations have already been shown in the lab to increase the ability of the virus to infect cells

All of these build a case for a virus that can spread more easily, says the BBC's health and science correspondent, James Gallagher.

Experts say the leading vaccines developed in recent months should still work.