Greater Manchester Police said the remains were found near Eccles Old Road at around 8.10am on Tuesday.
Detective Chief Inspector Colin Larkin from the force's major incident team called the news “extremely alarming.”
"Clearly, we're looking at suspicious circumstances surrounding the discovery of the body and are doing everything we can at the scene to gather as much evidence as possible,” he said.
"This is why you'll see a number of officers and specialist units close to Eccles Old Road and why parts of the area will be cordoned off.
"I appreciate that this news is extremely alarming for people in the local area but should anyone have any information, whether that is about what happened or whether they noticed something suspicious, they need to get in touch with us as a matter of urgency.
"We have a highly skilled team of detectives working on this case and will provide updates as and when we are able to do so but for now, I thank you for your patience that allows us to continue with our inquiries."
Additional reporting by PA.
