"I'm from Hubei Province. Go Beijing! Thank you to all the country for supporting Hubei when the outbreak happened there. Now is the time that I should repay you for your help."

These words were written on the back of a girl dressed in a protective suit, volunteering to transport food to people whose residential compounds in Beijing are closed-off.

The girl works at a convenience store near Xinfadi market in the south of the city and delivered fresh vegetables and some instant food to people in need. The photo of her wearing a hazmat suit and carrying vegetables and eggs in her hands has gone viral on Chinese social media with some netizens saying "Go! China and we go through the hardship together."

As coronavirus cases linked to the market were reported earlier this month, the city has been on alert for a second wave of the infection. Residents who have been to Xinfadi or had contact with people from there were advised to report to their neighborhood committee and self-quarantine for 14 days. Some residential compounds in close proximity to the market have also been closed off in case the disease breaks out.

The Beijing authorities have arranged nucleic acid testing for people who have been to the market and who live nearby. A list of 98 hospitals across the city have also been announced to accept residents' reservations for testing.

According to the Beijing's COVID-19 response team, 356,000 people have been tested, including market staff and residents. A total of 100 medics from across the city have been sent to Beijing Ditan Hospital for support, where all confirmed cases are being treated.

Some testers gone into residential compounds to test residents outdoors. Photos and videos showing doctors and nurses conducting tests under the scorching sun and getting soaked with sweat have made a splash online.

A restaurant owner in the city's Miyun District moved her four portable air conditioners outside to help cool the medics who were heavily wrapped with protective gear. Ms. Liu said, "They are protecting us and we are taking care of them. Facing disaster, the Chinese are united."

On Weibo, netizens initiated a campaign with the hashtag #Trust Beijing# to stay united. Posts showing respect and understanding between residents, medical staff and social workers have been sweeping across the platform.

A cartoonist based in the neighboring city of Tianjin drew a new work incorporating Beijing's local specialty of fried bean sauce noodles (Zha Jiang Mian), in which a caricatured bowl of noodles is being tested for its temperature by a doctor while special dishes from other parts of the country are waiting for it outside.

The cartoon entitled "Stay calm, fried bean sauce noodles" is a new work by the artist to show Chinese people's unity. Her previous work showing Wuhan's traditional hot dry noodles hospitalized while food from other regions of China are seen waiting outside the ward gained popularity online.

One netizen commented below the post, "Go Beijing! We're with you. Don't panic. We are staying united and going through the hardship. Hope everyone is safe and sound after the pandemic."

Beijing upgraded its COVID-19 emergency response from level three to two, which is "severe," on June 16. Schools have been shut and some flights to and from Beijing have been canceled.

According to the latest data from the Chinese health authorities, Beijing registered 21 new confirmed cases for Wednesday and the total in the city has reached 158 since June 11.