The five preliminary positive cases today were said to be two customers and three restaurant staff. The cluster has so far seen 11 people contracted the virus, with eight of them being customers.

One of the customers went to the restaurant for lunch on February 18, while the seven others went the next day in the afternoon.

“As some of them do not know each other, it is believed that the restaurant may have been the place where transmissions occurred,” said the center.

The Centre added that they are proactively following up to investigate whether the infections of the cases are related, so as to stop the potential risk of a further spread of the virus.

A spokesman for the Centre also urged those who visited the restaurant from noon to 3pm on February 19 to call the CHP's hotlines at 2125 1111 or 2125 1122 as soon as possible to facilitate epidemiological investigations and contact tracing.

Authorities yesterday included the restaurant in the compulsory testing notice, requiring any person who had been present at the restaurant at any time during the period from February 18 to February 24 to undergo testing by February 26.