Calgary police are renewing their appeal for the public's help in locating an 11-year-old boy who went missing Thursday morning, releasing an additional photo and urging residents in northwest Calgary to search their properties.Investigators say Parker was last seen between 11:08 a.m. and 11:41 a.m. at his day home in the 0 to 100 block of Connaught Dr. N.W.Police believe he was shirtless when he disappeared and was wearing grey shorts, black Skechers shoes and black noise-cancelling headphones.Officers are asking residents, particularly those in and around the Cambrian Heights neighbourhood, to thoroughly check backyards, unlocked sheds, garages and other places where a child may seek shelter or hide.Around noon, clothing believed to belong to Parker was found in the 0 to 100 block of Northmount Drive N.W.Police say Parker is approximately 4-ft., 11-ins., 90 lbs. and has brown hair and brown eyes.Investigators said Parker has a medical condition, heightening concerns for his safety and well-being.After exhausting investigative leads, police have turned to the public for assistance. Authorities said there is currently nothing to suggest foul play was involved.While the case does not meet the criteria for an Amber Alert, the Calgary Police Service is working with the Missing Children's Society of Canada to issue a missing child alert in an effort to locate him.Anyone with information about Parker's whereabouts is asked to contact the Calgary Police Service at 403-266-1234 or provide anonymous tips through Crime Stoppers.