The new H7N9 bird flu strain has killed 45 people on the Chinese mainland since the first human infection was confirmed in late March, reports the official Xinhua news agency.

A total of 135 H7N9 cases have been confirmed, with 134 on the mainland and one in Taiwan, director of the Chinese Centre for Disease Control and Prevention Wang Yu was quoted as saying on August 15.

Wang was speaking at an international symposium on the prevention and treatment of new types of influenza.

"There are still many unknown conditions relating to the H7N9 bird flu virus as well as diseases that might result from it, and the risks of a flu pandemic caused by a new type of avian influenza virus should not be underestimated," Wang said.-VNA