HSBC, Standard Chartered and other banks in Hong Kong closed branches or curtailed their working hours on Monday after a spike in the number of new coronavirus cases in the Asian financial hub.
Hong Kong recorded more than 100 cases in a 24-hour period over the weekend, the most since the pandemic took hold in late January.
The rise in cases took the tally close to 2,000 patients, 12 of whom have died.
Hong Kong banks shut scores of branches in late January when the first wave of the coronavirus cases hit the city. These later reopened as case numbers dropped.
Bank of China (Hong Kong) said in a statement on Monday it would suspend services at nine branches due to the spread of the virus. It had already suspended services at three branches, one of which reopened on Monday.
HSBC said in a separate statement it would temporarily close two business centres for commercial banking and three mobile branches operating from trucks, and shorten operating hours at all branches.
HSBC subsidiary Hang Seng Bank closed one branch for 14 days for deep cleaning after a member of staff preliminarily tested positive for COVID-19, it said on Sunday.
Standard Chartered and Bank of East Asia said they would shorten branch opening hours.
On Sunday, Hong Kong Chief Executive Carrie Lam announced tighter coronavirus restrictions with non-essential civil servants told to work from home.
Amusement parks, gyms and 10 other types of venues will remain closed for another seven days, while a requirement for restaurants to only provide takeaway after 6:00 pm was extended. Face masks will be mandatory in indoor public areas.