Beijing's top health authority will launch a mosquito-control campaign in mid-May to guard against the increasing risk of dengue fever, the Beijing Municipal Commission of Health and Family Planning said on Wednesday.

During the campaign, which will run until August, health authorities will focus on cleaning public places to remove excessive water and prevent mosquitoes from breeding, Liu Zejun, a member of the commission in charge of disease control and prevention in the city, said at a news conference.

Health authorities will mobilize the public to remove pools of water from places such as public restrooms, residential areas, parks, construction sites and garbage recycling stations, he said.

Other steps to control mosquitoes include releasing mosquito-eating fish in lakes and ponds and applying pesticides in areas where removing water is difficult, such as underground sewage systems, he said.

The Beijing Municipal Commission of Health and Family Planning has trained 16 professional mosquito elimination teams to help with the work, he said.

Studies by disease control and prevention experts have found that the density of Aedes albopictus, a kind of mosquito that is the major medium for transmission of dengue fever, has been increasing in Beijing for several years, said Zeng Xiaopeng, deputy director of the Beijing Center for Disease Prevention and Control.

In 2013, they accounted for 3.5 percent of all mosquitoes in Beijing, but the proportion rose to 14 percent last year. That means a higher risk of dengue fever, which can cause death in serious cases, he said.

Dengue fever outbreaks have occurred in some areas of South China, but sporadic imported cases have been spotted in recent years in northern areas, including Beijing, due to the spread of the virus, Zeng said.

Mosquitoes become more active with rising temperatures, and their density peaks in July and August in Beijing, he said.

Health authorities are prepared for outbreaks of infectious diseases including dengue fever, and emergency plans are ready, he said.