An ambulance is seen in front of the Emergency Department entrance at University College Hospital in London, Britain, on April 1, 2020. According to the Department of Health and Social Care, the number of confirmed COVID-19 cases in Britain reached 29,474 as of Wednesday morning, an increase of 4,324 in 24 hours. (Photos: Xinhua)

The BT Tower displays a message "Stay at home" in London, Britain, on April 1, 2020. According to the Department of Health and Social Care, the number of confirmed COVID-19 cases in Britain reached 29,474 as of Wednesday morning, an increase of 4,324 in 24 hours.

The BT Tower displays a message "Save lives" in London, Britain, on April 1, 2020. According to the Department of Health and Social Care, the number of confirmed COVID-19 cases in Britain reached 29,474 as of Wednesday morning, an increase of 4,324 in 24 hours.

The BT Tower displays a message "Protect the NHS" in London, Britain, on April 1, 2020. According to the Department of Health and Social Care, the number of confirmed COVID-19 cases in Britain reached 29,474 as of Wednesday morning, an increase of 4,324 in 24 hours.

The BT Tower displays a message "Stay at home" in London, Britain, on April 1, 2020. According to the Department of Health and Social Care, the number of confirmed COVID-19 cases in Britain reached 29,474 as of Wednesday morning, an increase of 4,324 in 24 hours.