KATHMANDU, Sept. 18 (Xinhua) -- A surge of influenza, including seasonal flu and swine flu, has been detected in Nepal's eastern Saptari district over the past weeks, according to authorities.

The Epidemiology and Disease Control Division under the Ministry of Health and Population confirmed that the flu has been detected in Kanchanrup and Hanumannagar Kankalini Municipality in Saptari which borders India.

Prakash Shah, chief of the Epidemiology and Disease Control Division, told Xinhua on Tuesday that "seasonal flu has mostly affected children, elderly, women and pregnant women in Saptari district. Since we have set up health camps with expert medical professionals in the pockets areas, the situation is under control."

The division chief said that among 24 collected samples of throat swab from the area, swine flu was detected in one case and Influenza A positive was detected in 12 cases.

"Seasonal flu is common so we have asked the general public to remain alert and adopt preventive measures to remain safe from the flu viruses," Shah, who visited the affected district, told Xinhua.

He further said that at least four persons have died in the district due to viral infection with secondary bacterial infection.

The government has launched free health check-up camps at different locations following the complaints of high fever, headache, cough and sneezes by local residents. World Health Organization (WHO) Emergency District Support Officers have also been mobilized in the affected area.

The Epidemiology and Disease Control Division informed that at least 3,500 patients of seasonal flu have been treated in the past one month.

Following the possibility of a flu outbreak, local authorities have directed to close the schools in at least two municipalities of Saptari district. Similarly, information, education and communication (IEC) materials have been distributed in the affected areas to raise the awareness of local residents.