Amid mounting concern over a new strain of COVID-19 detected in the UK, the Delhi government on Tuesday said it will check the health condition of passengers, who have arrived here recently from the UK, by visiting their houses.

All passengers arriving from the UK are now being tested for COVID-19 at Delhi airport, Health Minister Satyendar Jain told reporters.

"The Delhi government is on alert in the wake of a mutated coronavirus strain detected in the UK. The situation is being closely monitored and mandatory tests are being conducted at the Delhi airport for all passengers arriving from that country," he said.

Jain said Delhi has fought difficult battles with COVID-19 and all efforts will be made to ensure that the improvement made in the management of the pandemic is "not reversed".

The Civil Aviation Ministry on Monday said all flights from the UK to India and vice versa will remain suspended from Wednesday to December 31, in view of the emergence of a mutated variant of the coronavirus there.

In the last two weeks, about 6000-7000 people have landed at Delhi airport, many of whom would have travelled to other places like Punjab from thereon, Jain said.

"We will go house-to-house and do check-up of passengers to assess their condition, and also advice them to isolate themselves for some time," he said.

Sources said passengers coming from the UK are being administered RT-PCR tests at the airport. Anyone testing negative but with symptoms will be kept in institutional isolation and those testing negative will also be asked to go into self-isolation for seven days, they said.

Jain has also appealed to those who have recently come from the UK to monitor their health and go for tests at the slightest of COVID-like symptoms, and inform the government.

Asked about the threat of the new virus strain entering Delhi, he said, "CM Kejriwal had appealed to the Centre to close flights from the UK, and it had been done. So, we are doing everything possible to contain the spread".

A new vaccine is being prepared to treat COVID-19, he said.

Asked if the new strain could negate its efficacy, he said, "Only scientists and ICMR can comment on it".

Delhi recorded 803 fresh cases of COVID-19 on Monday, the lowest since August 17, taking tally to over 6.17 lakh, even as the death toll increased to 10,304 with 27 new fatalities.

"We recorded such a low number of cases and a positivity rate of 1.29 per cent," Jain said.