Beijing reported a COVID-19 family cluster of four people on Tuesday morning and the risk level of the residential community was raised to medium afterwards, according to Pang Xinghuo, deputy director of the Beijing Center for Disease Control and Prevention, at a news conference on Tuesday.

The four people -- a couple, their daughter and the daughter's grandmother -- were confirmed as COVID-19 patients on Tuesday morning.

Chaoyang district, where the patients work and study, had triggered an emergency response on late Monday afternoon when the local authority received information of the potential risk.

Up to 16 schools in the district had suspended on-campus classes starting Tuesday.

The two major schools -- one primary and one middle school -- have conducted nucleic acid testing for all teachers and students.

By Tuesday morning, 596 people from the primary school and 1,329 people from the middle school had negative nucleic acid test results. The remaining people are waiting for their results.

By 11 am Tuesday, Beijing reported 33 confirmed local cases and two asymptomatic cases during the latest outbreak, said Pang.

"Beijing is still facing a complicated epidemic control situation and safety precautions on all forms of transportation need to be strengthened to reduce infection risks," she said.

The city government continues to ask its residents not to leave Beijing unless absolutely necessary.

The authority also encourages residents not to have weddings or gatherings of family and friends at present.