A new Covid variant, dubbed Arcturus, has been found in the UK as the same strain of the virus forced India to bring back some of its mask laws and run drills in its hospitals.
The Omicron sub-variant XBB.1.16 has caught the attention of experts around the world as it caused a recent surge of infections in India.
Now, the UK Health Security Agency (UKHSA) has confirmed that it is present in the UK, but that there are under 100 cases.
The Mirror understands that there were 66 sequences in the UK - these do not necessarily translate to 66 cases - but since then more instances of the virus have been brought in internationally.
But in India it is quickly becoming the driving variant, and the country's health ministry even went as far as to launch mock drills this week in an attempt to see if hospitals were prepared to deal with a possible influx of patients.
Wearing face coverings in public has been made compulsory again in some states, being the first time in more than a year for some.
Figures from Our World in Data, run by Oxford University, show how cases have spiked in India in recent months.
The Mail reported that there are fears that Arcturus is the most contagious sub-variant of Omicron yet.
In India's southern state of Kerela, Health Minister Veena George reintroduced masks for the elderly, pregnant women, and those with underlying conditions.
This week, case numbers throughout India rose by 3,122 in a single day, but India's severe reaction has been partly informed by a devastating second wave the country suffered - and a desire from politicians to avoid a repeat.
In a press conference, Maria Van Kerkhove, the World Health Organisation's technical lead for COVID-19 response, said: "Omicron is the variant of concern that remains dominant world wide and there's still more than 600 sublineages in circulation.
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"One of the variants that we are looking at, is the variant that we have under monitoring. This is the XBB.1.16.
"It's very similar in profile to XBB.1.5. But has one additional mutation in the spike protein which in lab studies shows increased infectivity as well potential increased pathogenicity. So it's one that we are monitoring. It has potential changes that we need to keep a good eye on."
XBB.1.16 was first documented on the 23rd January this year, and was designated a variant under monitoring by 22nd March.
In publicly available documents, the UKHSA said that it had been detected in the UK in the past 12 weeks.
Like other international and global health bodies, it flagged new mutations present in XBB.1.16 that could cause problems.
There has been no reported increase in severity in cases caused by Arcturus, which has been detected in at least 22 countries.
Raj Rajnarayanan, assistant dean of research and an associate professor at the New York Institute of Technology campus in Arkansas called XBB.1.16 "the big dog".
Advisory Board reported he added: "It's picking up mutations that are common in other variants that will increase its advantage further."
Meanwhile Ryan Gregory, a biology professor at the University of Guleph in Canada called Arcturus' rise in India "concerning".
