China will shut poultry markets in certain districts of two cities after H7N9 bird flu infections were detected, state media reported on Sunday, the latest incidents in this year's more severe outbreak of the virus.

A 44-year-old man who sold poultry at a farmers market in southwestern Sichuan province's Zigong city was diagnosed with H7N9, China News Service reported. Local authorities announced a one-month halt to poultry markets in the city's Ziliujing district from midnight on Monday.

Separately, a 74-year old man who had visited poultry markets in Shandong province's Binzhou city was also diagnosed with H7N9, China Central Television reported. Binzhou authorities will temporarily halt poultry markets in three of its districts.

Bird flu can jump from poultry to humans. Human cases of bird flu have been unusually high for China since last year, with three times more fatalities from H7N9 in the first four months of the year than in all of 2016. But deaths fell in April for the third consecutive month.