Concerned neighbours in Long Eaton described the moment a teenager with a cut to his face was taken to hospital as police taped off the area.
Officers from Derbyshire Constabulary were called out to a report of a robbery in College Street.
A force spokesman said the incident happened at about 6pm on Friday (February 19).
He said: "A 17-year-old boy had his phone stolen by someone who then ran off.
"He had a facial injury and was checked at hospital but later discharged."
Witnesses described the police presence - as one man recalled the moment the boy was taken to hospital.
Retired Darryl Phillips, 57, who lives in Long Eaton, and used to work on the waterway, said: "I saw loads of police pull up, ambulances and that.
"I have seen the lad with the cut face walk into the ambulance.
"It happened around about 6 o'clock, it was early.
"I wondered what went off. They had got it all taped off, I knew then something serious had gone off.
"It's the first time I have seen anything down here like that."
Adam Chaudhry, 54, who lives in the town, said he saw police after leaving his sister's home.
He said: "It was about 20 to eight, I just left her road, Willoughby Avenue, there was a police car that went past me towards town.
"I noticed there were a few cars up there. They had their blues and twos on.
"I would say there were about three, there might have been a police van as well, I saw some lights higher up."
Mr Chaudhry, who used to live in London and works for Amazon, explained police incidents were out of character for the town.
"It's extremely safe, it's a very nondescript area," he added.
"Compared to where we used to live it's nothing."
His sister Sophia Chaudhry, 56, an NHS project manager, said: "If you hear sirens you think obviously something must have happened.
"Nothing really much happens around here and I have been up here for four-and-a half to five years."
While he wasn't aware of what happened, Paul Mellors, 66, a semi-retired accountant from Long Eaton, said: "There's been a few incidents over the last few months.
"It is (concerning), we are not going anywhere, we are not out and about.
"Because of the area we are always security conscious and we always have been.
"We are more worried about this thing with dogs being pinched."
