Delhi government has asked municipal bodies to strictly carry out fogging exercise across the city and take steps to contain mosquito breeding. At a review meeting held yesterday, state Health minister A K Walia issued the instructions to South, North and East Delhi municipal corporations, NDMC and Delhi Cantonment Board to carry out fogging extensively in this regard. Mr. Walia asked municipal corporations to particularly check roof top water tanks and construction sites as they are the most fertile breeding ground for mosquito causing dengue. The minister also urged citizens to cooperate with mosquito breeding checkers so that spread of the vector borne disease can be controlled.Dengue continues to spread in the capital with 35 patients testing positive yesterday, taking the number of affected to 720 so far.