Covid lockdowns have come to an end at two residential blocks sealed off overnight for compulsory testing.

No new Covid cases were found, but the test result of one specimen is still undergoing the verification process.

The buildings are Tower 3 of Grand Central in Kwun Tong and Fu Yuet House at Fu Cheong Estate in Sham Shui Po.

But there's still no word yet on the compulsory testing at Yat Kwai House in Kwai Chung Estate.

The lockdowns were linked to a 17-year-old boy, who may have the delta variant, a 12-year-old boy, and a 53-year-old man who works at the Cathay Pacific Cargo Terminal.

The residential blocks were cordoned off between 6.30 pm and 8.45 pm on Wednesday. More than 3,100 people were tested.

On Wednesday, Hong Kong confirmed 16 Covid infections, including seven thought to have been acquired locally. The source of infection of two of the cases - a kindergarten teacher and a 79-year-old man - remain a mystery.