New Delhi , India ( CNN ) -- A dozen Australian swimmers have fallen ill at the beleaguered Commonwealth Games in India , officials say . The swimmers are reporting a higher percentage of diarrhea than other athletes at the games , said an Australian official who spoke on condition of anonymity . Two Australian swimmers have withdrawn . `` The Commonwealth Games Federation chief , Mike Fennell , asked at a press conference Thursday that immediate tests be conducted on all pools . The organizing committee conducted the tests and have come back and said the water quality in all pools is clear , '' said an official with the Commonwealth Games Federation , who also spoke on condition of anonymity . When asked whether there was a problem with the food , he said : `` We are confident the food in the games village is up to international standards . Since September 12 , more than 700 tests have been conducted on the food and all independent tests have passed with flying colors . '' The federation is exploring what else could have sickened the athletes . The illnesses threaten to further mar the games , which have been widely criticized . Organizers scrambled to pull together the event after a pedestrian bridge at a stadium collapsed last month and officials called accommodations at the athletes ' village uninhabitable and filthy . It 's the first time India has hosted the international sporting event between countries of the former British Empire . The games , held every four years , include many Olympic events and other sports traditionally played in those countries . The games gave India an opportunity to promote a shiny image as an emerging power . The government spent billions on a new international airport , additional metro lines and fresh landscaping along dingy Delhi roads . Problems piled up before the games , however . Last month , gunmen fired on a tourist bus in New Delhi and injured two Taiwanese tourists . A car blaze turned out to be a crudely manufactured bomb . And a militant group warned that it planned to target the games . Indian law enforcement authorities responded with a heightened security plan , placing thousands of extra forces on the streets of the capital . Two world-class athletes canceled their trips , citing security and health concerns . Entire teams threatened to do the same , while others delayed their arrival date . Elena Baltacha , a tennis player picked to represent Scotland at the games , pulled out . `` I am incredibly disappointed , because I was really excited about playing for Scotland , but conditions in Delhi are such that going there would pose too high a risk to my health , '' she said at the time . India remains a developing country with millions of poor people , and risks such as dengue fever . On Monday , doctors confirmed a case of dengue fever in an official with the Indian lawn bowls team at the Commonwealth Games . The 30-year-old man could have contracted the disease from outside the athletes ' village in New Delhi . He had complained of feeling sick a day after arriving at the athletes village last month , said a spokesman for the G.B . Pant Hospital in the city . Dengue is the most common virus transmitted by mosquitoes in the world . It causes as many as 100 million infections and kills 25,000 people every year . Dengue is found in tropical and sub-tropical climates worldwide , mostly in urban and semi-urban areas , according to the World Health Organization .
A dozen Australian swimmers have been sickened . They are reporting a higher percentage of diarrhea than other athletes . Pool water has tested clean , a games official said on condition of anonymity . Organizers are exploring what else could have sickened the athletes .