The patients, aged 8 to 33, arrived on a Turkish Airlines flight from Istanbul on August 1.
Three of them had received one dose of the BioNtech vaccine in the UK in either June or July.
Due to the positive test results, Turkish Airlines flights from Istanbul are being banned from landing in Hong Kong from Wednesday to August 17.
Officials also reported a handful of preliminary positive cases on Tuesday.
All 32 infections reported in the past fortnight were linked to overseas travel, and Hong Kong has recorded 11,994 cases so far.