North China's Tianjin municipality has seen an increase of 13.8 percent in the number of flu cases over the last year, according to the municipal disease prevention authority.

    The municipal health bureau has ordered local schools and kindergartens to carry out daily temperature checks on students, and hospitals to ensure that the chances of cross-infection between patients are reduced to a minimum.

    The disease prevention authority in Taiyuan, capital of north China's Shanxi province, has ordered local hospitals to report flu cases on a daily basis and remain on high alert to group infections. Construction sites have also been asked to conduct regular checks on migrant workers.

    The provincial health authority in northwest China's Shaanxi province has urged its disease prevention offices to provide prompt information to the press and keep the public informed of any major developments.

    "Although flu is rife in these northern cities, the chances of a large-scale flu outbreak in the near future are low," Mao Qunan, the Ministry of Health spokesman has said.

    "The flu is not caused by the H5N1 bird flu virus," confirmed He Xiong, deputy director of the Beijing Center for Diseases Control and Prevention (CDC).

    The sharp drop in temperature and poor air quality in north China have been cited as the main reasons for the rise in cases. The reluctance of people to pay for flu inoculations has exacerbated the situation. The cost of a flu jab for an adult in Beijing is 69 yuan, a price that is deemed out of reach of low-income groups, who tend to live and work in cramped conditions which increases their vulnerability to infection.

    Health experts have advised people not to go to crowded areas, a challenge in China's densely populated cities, and don face masks at the first sign of cold symptoms.