The three infected people, a woman and two children, arrived in the SAR on October 25 after originally setting off from Pakistan.
Another two new imported infections reported on Wednesday involved people who recently travelled to the SAR from the United States.
One of them, a 54-year-old air cargo crew member, had tested negative for Covid on October 19 before leaving Hong Kong two days later.
In light of a positive test after his return to the territory on October 25, officials have issued a mandatory testing order covering Graceful Mansion (Block H2) at Siena Two in Discovery Bay, where he lives, as well as other places he went to during the incubation period.