A new case of H7N9 bird flu was confirmed by the health bureau of east China´s Anhui Province on Tuesday, bringing the total number of positive cases in the province to four.

A 91-year-old man surnamed Wang from the county-level city of Tianchang, Chuzhou City, tested positive for the new strain of avian influenza on Monday. He is in a critical condition.

Thirty-five people who were in close contact with the patient have been placed under medical observation, but have so far shown no abnormal symptoms.

The neighboring Zhejiang Province reported two more infection cases Tuesday. An 84-year-old retired man surnamed Hong and a 62-year-old farmer surnamed Song were confirmed to be infected with the new strain of the virus. Both are in critical condition.

Meanwhile, east China´s Shandong Province has confirmed its first case of H7N9, according to the provincial health department.

As of Monday afternoon, a total of 104 H7N9 cases had been reported in China, including 21 that have ended in death.