Homer, AK -- At least 30 of 200 people attending a convention here were struck by gastrointestinal illness last weekend, according to a local newspaper.The Anchorage Daily News yesterday reported that the outbreak occurred during the annual convention of the Alaska Association of Realtors. State authorities received reports from about 30 people who suffered severe nausea, vomiting, or diarrhea, while the association reported about 50 people who fell ill, according to the newspaper. Nobody was reported hospitalized.The group met over four days at the Land's End Resort, starting Wednesday. People complained of illness beginning early Saturday morning, the newspaper reported.State health officials have not yet pinpointed the source of the illness and continue to investigate, according to the newspaper.Many of those who fell ill reported being sick for two to three days, typically a longer time than is the case with food poisoning, according to health officials that the newspaper quoted.