Brave bystanders tried to rescue a man who was being savaged by a dog by "chucking a tennis ball".
The 50-year-old was attacked this afternoon and suffered life-threatening injuries, police said.
Emergency services were called to Yewdale Gardens in Breightmet, Bolton, at around 1.20pm to reports that a man was being attacked by a dog.
An air ambulance attended the scene, along with a Bolton council Dog Enforcement Control Unit van, the Manchester Evening News reports.
Greater Manchester Police said the dog "has now been secured" and is "due to be destroyed".
There has been speculation that the man who suffered the attack might be the dog's owner.
Neighbour Sammi Lin-Lancelott said he heard the victim scream from a nearby garden and ran out to try and stop the attack.
She said: “He was a mess. He had puncture wounds everywhere.
“My partner chucked a tennis ball and that’s how the dog got off him.
“We called the police, got a blanket for him and kept talking to him so he did not pass out.
“He was in a really bad way. It was horrible.
“I hope he is okay."
Fellow neighbour Colbert Alleyne, said he had returned home from the shop to find the street taped off.
“There were police everywhere,” he said.
“It was chaos. I could not get in my house.
“The police told me a dog had attacked a neighbour.”
The man was taken to hospital, where he remains for treatment.
A police spokesperson said: "Officers were called to Yewdale Gardens, Bolton, at about 1.20pm on Thursday 6 May 2021 to reports a man was being attacked by a dog.
"North West Ambulance Service and an air ambulance attended and a 50-year-old man was taken to hospital with life-threatening injuries to his arm and face.
"A scene remains in place and enquiries are ongoing. The dog has been secured."
The ambulance service added: "An ambulance, advanced paramedic and air ambulance are currently attending an incident on Yewdale Gardens, Breightmet, following a 999 call at 13.32.
"One patient is now in hospital."