SAN FRANCISCO (KGO) -- San Francisco police are asking for help in tracking down a dangerous dog.Police say two middle school students were running at Joe Dimaggio Playground on April 3 when a dog bit them at the corner of Mason Street and Lombard Street.The dog is described as large and white with black and gray colored spots.It's owner is described as a white woman in her 30's wearing a white shirt and purple vest.Both students had bite wounds on their legs and were treated and released from a local hospital.The San Francisco Police Department is investigating the incident and has requested the public's assistance in identifying the dog in order to obtain information regarding the dog's vaccination record.The dog owner or anyone with information regarding this incident is asked to contact police at the Vicious and Dangerous Dog Unit at 1-415-553-9182.