Another 30,004 people in Britain have tested positive for COVID-19, bringing the total number of coronavirus cases in the country to 3,647,463, according to official figures released Sunday.

610 more lives have been lost within 28 days of a positive coronavirus test. The total number of coronavirus-related deaths in Britain now stands at 97,939, the data showed.

Earlier Sunday, British Health Secretary Matt Hancock said "early evidence" shows the lockdown restrictions in Britain are starting to bring the number of new infections down.

However, it is still a "long, long, long way" before coronavirus cases are low enough for the lockdown to be lifted, he told Sky News, adding that the National Health Service (NHS) remains under "enormous" strain.

"We should be worried enough, all of us, about this pandemic to follow the rules and it is just so important that people do," he said.

Meanwhile, Hancock expressed his concerns over the new COVID-19 variants not yet discovered.

"The new variant I really worry about is the one that is out there that hasn't been spotted," he said.

Prime Minister Boris Johnson has warned that the coronavirus variant first identified in Britain may be more deadly than the older variant.

The British government's Chief Scientific Adviser Patrick Vallance said "a lot of uncertainty around these numbers" remains but early evidence suggests the variant could be about 30 percent more deadly.

The new strain of coronavirus first identified in Kent, England, is thought to be up to 70 percent more transmissible. However, Johnson said that the current vaccines are still effective against the new variant.

England is currently under the third national lockdown since the outbreak of the pandemic in the country. Similar restriction measures are also in place in Scotland, Wales and Northern Ireland.