HONG KONG, Feb. 20 (Xinhua) -- A health official in the Hong Kong Special Administrative Region (SAR) has said that hospitals here were facing a "protracted war against flu" with the winter peak season expected to last for several more weeks.

Hospital Authority chief executive Leung Pak-yin made the remarks as Hong Kong's public hospitals saw a rush of patients on Tuesday as the four-day Lunar New Year holiday ended.

Meanwhile, the Center for Health Protection (CHP) of the Department of Health of the SAR government said Tuesday that in view of the continuous high level of seasonal flu activity and the end of the Lunar New Year holiday for schools soon, it had issued letters to schools to appeal for heightened vigilance and reinforcement of preventive measures to mitigate the impact of seasonal flu.

The SAR government's Secretary for Food and Health Chan Siu-chee has warned on Monday that the seasonal flu activity would remain at high level for a period of time and more patients were likely to show up at hospitals after the holiday.

The Department of Health has ordered an additional 44,000 doses of flu vaccine and they are expected to arrive in Hong Kong by mid-March, Chan said when visiting three public hospitals.

She added that she would also meet health experts to discuss enhancing Hong Kong's research on flu.