SHANGHAI, Jan. 20 -- Two H7N9 avian flu patients, including a medical worker, have died in Shanghai, local health authorities said on Monday.

A 31-year old male medical worker with the surname Zhang died at around 4 a.m. on Saturday while a 77-year-old male farmer surnamed Wu died at around midnight the same day, according to the Shanghai Municipal Commission of Health and Family Planning.

Both tested positive for the H7N9 virus posthumously on Sunday.

Shanghai has confirmed seven human H7N9 cases so far this year.

Zhejiang, a province located south of Shanghai, also reported six more cases of H7N9 avian flu on Sunday and Monday.

The new cases brought the number of infections in Zhejiang so far this year to 26, the most among all regions nationwide, according to the Zhejiang provincial commission of health and family planning.

All the six patients, five males and one female aged from 53 to 71, are in critical or severe conditions, it said.

Experts from the Zhejiang provincial center for disease control and prevention warned that with more live poultry markets being contaminated, more cases could be reported in the lunar new year holiday season due to increases in poultry consumption.

Human contractions of H7N9 have also been reported in Jiangsu, Fujian and Guangdong provinces.

The southern province of Guangdong reported its third H7N9 death on Monday.