FROM CNN WIRES:

Hong Kong (CNN) - Shanghai will temporarily close all its live poultry markets after an unusual strain of bird flu that has so far killed six people in China was found in pigeons on sale in the city.

The closure of the markets will begin Saturday, the Shanghai Municipal Government's press office said on its official microblog account Friday. It didn't say how long they would remain shuttered.

Authorities in Shanghai had already begun slaughtering all the birds at a market in the city where traces were discovered Thursday of the H7N9 avian flu virus, which had not previously been found in humans until a series of cases were reported in China this week.

This morning on "Early Start," CNN's David McKenzie reports on China's move to close poultry markets.

READ MORE: Shanghai closing all live poultry markets as China avian flu toll rises to 6