Video report by ITV News Reporter Stacey Foster
Leicester is being put under a localised lockdown to keep coronavirus outbreaks in the city under control after other measures tried by the government did not work, the health secretary has said.
The law will be changed in coming days to close all the city's non-essential shops after a spike in coronavirus cases was recorded - 10% of all UK infections in the past week were in Leicester.
Schools will also close to most pupils from Thursday as part of restrictions imposed.
How the other side of Leicestershire which escapes the local lockdown plans to reopen. Ben Chapman reports
"We've been putting in place measures in Leicester for some time now," Matt Hancock said, "but it was clear that we needed to take this further action".
"We put in more mobile testing units to find out exactly where the virus is, we also supported the council about the measures they can take and on top of that we've been working in the companies and factories where there have been clusters and outbreaks to try to get those under control by asking people to isolate if they have been at risk."
The health secretary said similar measures had been taken in other parts of the country too "but clearly there was more transmission, more cases in Leicester".
Measures in other parts of the country "brought the virus under control, unfortunately in Leicester it didn't and therefore we had to take these much more significant measures", he said.
He added: "Closing schools and closing shops is not what anybody would want to do but they are necessary because the more targeted measures had not brought the virus under control."
Mr Hancock told ITV News the government is recommending against travel in and out of the city, "unless it's absolutely necessary", but said "we do have powers in the coronavirus act that we passed at the start of this crisis, to legally enforce restrictions on travel".
The health secretary added how that is "another big step and I'd rather not take it - my strong preference is that people will adhere to this very clear guidance".
The local lockdown means the city will not be allowed to ease restrictions along with the rest of England on Saturday, meaning pubs, bars, cafes, restaurants, barbers and hairdressers will not be allowed to open their doors.
When shielding advice relaxes across England on Monday - allowing the most clinical-vulnerable to spend more time outside - these changes will not take place in the city.
Mr Hancock told BBC Breakfast on Tuesday that the government was not making non-essential travel illegal, but said it would if it had to.
He added people should stay at home where possible.
“On shops, the non-essential retail, we will be closing them by law and changing the law in the next day or two to put that into effect," Mr Hancock said.
“We are also not releasing the legal measures that lift the lockdown for the rest of the country."
He told ITV News that the new local lockdown in Leicester shows "we all need to remain alert, we need to remain vigilant, this isn't over yet".
One reporter questioning the health secretary suggested the test and trace system hadn't worked in the city, pointing to the local authority's three-week old suspicion about a rise in cases.
Mr Hancock denied it, saying increased testing allowed officials to find out more about the virus in Leicester before the lockdown was imposed.
Boris Johnson announced during his speech about 'Project Speed' on Tuesday that there is no surprise an area needed to be locked down.
“On Leicester, let me just say that, obviously, we will be in constant communication with the authorities in Leicester, but, also, monitoring it nationally.
“And, insuring that as and when the data changes, and the situation improves, then we will take steps to ease the measures that we have had to enforce.”
Leicester mayor Sir Peter Soulsby says the city will next extra support after the end of the imposed lockdown to aid its recovery.
“I’m very very concerned obviously about the impact on the well-being of the city in general and the health of the people in the city, but also about the economy of the city," Sir Peter said.
“One of the things we’ve been stressing to the Government over recent times is that if Leicester is to be locked down and its economy put in limbo for a little longer, we will need support that was given earlier in the pandemic, throughout the UK, restored here in Leicester.”
The mayor told reporters that the local lockdown announced last night “was I think more wide-ranging than we’d anticipated”.
He added: “I’m really grateful for that, because while it is a pain for us and a nuisance for us in the city to be subject to that level of restriction and to have the clock turned back in the development of the virus, it is nonetheless something that has some realistic prospect of being effective.”
He also said that leaders are still trying to learn more about where the virus is in the city, saying: “We do need still to know more about where it is in the community.
“I’ve had lots of speculation and lots of questions about where it is in the community and we have not as yet been able to give satisfactory answers even to ourselves, no matter anybody else, about which parts of the community need the intervention.
“Which neighbourhoods, which communities, indeed which streets.”
Labour leader Sir Keir Starmer said his party supported tougher measures in Leicester but the Government had “been slow about it” and many people were left with their questions unanswered.
As well as the city centre, the local lockdown will also apply to Oadby, Birstall and Glenfield in the county.
On Tuesday, Leicestershire County Council released a map detailing the area covered by the tighter restrictions.
Watch Science Editor Tom Clarke's report from Monday's News At Ten
According to Public Health England data, almost 3,000 Covid-19 cases have been confirmed in Leicester since the start of the coronavirus epidemic.
Of these, 944 cases were reported in the last two weeks.
The number of coronavirus cases in Leicester is currently three times higher than the second highest city in the UK.
There was an “unusually high” incidence of coronavirus in children in Leicester, the Health Secretary has said.
Mr Hancock told BBC Breakfast that while work was still being done to understand why Leicester had been so badly affected by the outbreak, extra testing had found under-18s testing positive for the virus.
He said that even though children are less likely to get ill from the disease, the decision to shut the city’s schools was made to try to halt further transmissions.
Mr Hancock added: “We have sent in a lot of extra testing into Leicester over the last 10 days or so and one of the things we have found is that there are under-18s who have tested positive and therefore, because children can transmit the disease – even though they are highly unlikely to get ill from the disease – we think the safest thing to do is close the schools.
“The reason I said what I did last night about Leicester is that it is an unusually high incidence in children in Leicester.”
Speaking in the House of Commons late on Monday, Mr Hancock announced that further measures in Leicester will be put in place to help tackle the outbreak, including the setting up of a walk-in testing centre for those with coronavirus symptoms.
He also urged residents in Leicester if they have any Covid-19 symptoms they "must come forward for a test."
Coronavirus: Everything you need to know