Authorities in Wuhan say they have tested nearly all of the city"s 12 million residents for coronavirus, writesABC.

The Chinese city reported new clusters of infections last week, when seven migrant workers at the Wuhan Economic and Technological Development Zone tested positive.

Mass testing in the city, which recorded the world"s first confirmed case of coronavirus in late 2019, began the next day.

Nine people in "closed-off" communities tested positive, local authorities told a press briefing on Sunday.

"So far, a total of 11.2858 million people have received tests, basically covering all the municipal population except the college students who have returned home from the city for summer vacation and children aged under six," Li Tao, deputy secretary general of the Wuhan municipal government, said.

"We will continue checking and making arrangements for those who have missed the tests."