SHANGHAI -- A total of 20,536 chickens, ducks, geese and pigeons from a live poultry trading zone in Shanghai were slaughtered after the H7N9 virus was detected there, Shanghai authorities said Friday.

Huhuai Agricultural Products Wholesale Market, located at Dongjing Township of Songjiang District, was closed earlier this morning after the H7N9 bird flu virus was detected from samples of pigeons in the market.

Excrement, contaminated fodder, padding from cages as well as waste water in the market have been disinfected before disposal, according to the agricultural commission of Shanghai municipal.

As of 6 a.m., the whole market had been cleaned.

The Agricultural Commission, Industry & Commerce Administration, Health Department of Songjiang District and the government of Dongjing Township, worked together in the disposal overnight.

Relevant departments are still investigating and tracking where the infected pigeons came from, and have launched investigations at other agricultural product markets in the city.

Six people, who had close contact with the poultry, are under medical observation. Their blood samples have been sent to Shanghai Municipal Center of Disease Control & Prevention.

Vendors in the market have been paid compensation for their poultry, according to the agricultural commission.

China has confirmed 14 H7N9 cases -- six in Shanghai, four in Jiangsu, three in Zhejiang and one in Anhui, in the first known human infections of the lesser-known strain. Of the cases, four have died in Shanghai and there have been two losses of life in Zhejiang.