A man was today in police custody after he was arrested on suspicion of the attempted murder of a police officer.
He was being questioned by police after a female officer was left seriously injured following an axe attack.
The officer, who has not been named, lost a finger when she was attacked with a hatchet in the Gleadless area of Sheffield, and also suffered a fractured skull and a broken leg.
A member of the public who dragged the officer to safety said she was attacked by a man who was "chopping bits off her".
She was the most seriously hurt of five police officers injured in the incident on Wednesday night after she and male colleague responded to what they thought was a "routine" domestic incident.
The incident began at a flat but finished in a nearby Co-op store where the attacker was finally subdued by officers using batons and a Taser.
Simon Ellis, 46, described how he witnessed the attack and then pulled the stricken officer into his flat in Plowright Close as she feared the man would kill her.
Mr Ellis said it was "a frenzied attack, chopping at her with the axe", adding that the injured officer shouted: "He's going to kill me, get him off me."
Mr Ellis said he dragged her by her body armour into his hallway, where he said paramedics worked on the officer for more than an hour. The attacker fled from outside the block of flats when the badly injured officer's colleague arrived, he said.
Chief Superintendent David Hartley of South Yorkshire Police said armed officers were on their way to the scene at the time of the arrest but were not deployed.
Mr Hartley said he had heard reports of the brave actions of members of the public to help his officers and he hoped to be able to thank them personally later in the day.
Mr Hartley said the incident was not related to the murder of a 22-year-old woman in Gleadless on Tuesday.