Speaking after spending half an hour inspecting the area, Cheung said they have met the target with almost 7,000 people being tested on Saturday.
Cheung added they had been knocking on every door in the area and had taken details of 6,000 residents to ensure that they get tested, but 45 households did not answer the door on Saturday.
He said they were also unable to find out the number of people who fled the area before the lockdown, but there “shouldn’t be many”, and health officials would continue going door to door to speak to people.
A further announcement is to be made on Sunday night when all test results come back.
Cheung said the first-ever lockdown in the city shows how decisive the government is in taking appropriate action, adding that it will learn from the experience being as there are bound to be “inadequacies”.
He said more lockdowns could be implemented in other districts when necessary.
The government imposed the lockdown early on Saturday in an area of Jordan that runs from Woosung Street in the east, Nanking Street in the south, Battery Street in the west, to Kansu Street in the north.
Nobody is being allowed to leave until everyone in the area has taken a test and the results have been confirmed.
The government has faced complaints that it was slow to communicate what was going on and of lengthy waits for testing.