A "very small" number of coronavirus cases in Norfolk have been caused by the Indian variant of Covid-19, public health bosses have revealed.

Scientists are keeping a close eye on the spread of the variant across the UK and prime minister Boris Johnson has said the government is "anxious" about it.

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B16172, first identified in India, was last week designated as a "variant of concern" by experts from Public Health England after small clusters of cases were detected across the country.

And Dr Louise Smith, Norfolk's director of public health, confirmed there had been cases in the county.

Wymondham & Attleborough Mercury: Dr Louise Smith, director of public health for Norfolk. Picture: Norfolk County CouncilDr Louise Smith, director of public health for Norfolk. Picture: Norfolk County Council (Image: Norfolk County Council)

She said: "We’re seeing cases of the variant first identified in India being recorded across the country and, like in other parts of the country, there has been a very small number in Norfolk.

"We continue to work closely with Public Health England which is monitoring the situation closely.

“The ways to prevent spread of this variant remain the same – getting a vaccination when it’s offered, getting tested regularly, following current lockdown restrictions – including quarantine rules for travellers - keeping our distance from others, and wearing face coverings as appropriate.

"And from next week when more indoor meeting is due to be allowed, allowing in lots of fresh air when meeting up indoors."

The Scientific Advisory Group for Emergencies (Sage) was holding a meeting on Thursday to discuss the spread of the Indian variant.

And prime minister Boris Johnson has said he has ruled nothing out over ways of stemming the spread - as the country gets ready for more easing of coronavirus restrictions on Monday.

Wymondham & Attleborough Mercury: Prime Minister Boris Johnson during a media briefing in Downing Street.Prime Minister Boris Johnson during a media briefing in Downing Street. (Image: PA)

Mr Johnson said: "It is a variant of concern, we are anxious about it.

"At the moment there is a very wide range of scientific opinion about what could happen.

"We want to make sure we take all the prudential, cautious steps now that we could take, so there are meetings going on today to consider exactly what we need to do.

"There is a range of things we could do, we are ruling nothing out."

On Wednesday, the European Medicines Agency said it was "pretty confident" vaccines currently in use would be effective against the Indian variant - a view echoed by some British scientists.

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Bolton has one of the highest rates of the Indian variant in the UK, thought to be mostly concentrated in the under-25s, with surge testing being used.

In Blackburn, extra vaccine doses have been secured so all people aged over 18 can be offered the jab from next week amid rising cases there.

Asked if local lockdowns were possible, Mr Johnson said: "There are a range of things we could do, we want to make sure we grip it.

"Obviously there's surge testing, there's surge tracing.

"If we have to do other things, then of course the public would want us to rule nothing out.

"We have always been clear we would be led by the data.

"At the moment, I can see nothing that dissuades me from thinking we will be able to go ahead on Monday and indeed on June 21 everywhere, but there may be things we have to do locally and we will not hesitate to do them if that is the advice we get."

Professor Robert Dingwall, a member of Nervtag (New and Emerging Respiratory Virus Threats Advisory Group) - an expert committee which advises the government on the threat posed by new respiratory viruses - said that while B16172 may be capable of becoming the dominant variant in the UK, the risk of a surge in deaths or hospital admissions remains low.