Two men and a woman arrested after a police officers was attacked in Doncaster remain in custody this morning.
Police arrested the trio after a 45-year-old police officer was seriously injured in Cherry Tree Road, Hexthorpe, yesterday morning.
Detectives said the officer, who suffered head injuries, was attacked shortly after a black Fiat Punto crashed into a wall in Cleveland Street at 7.30am.
Three people believed to have been in the car at the time fled from the scene towards Cherry Tree Road.
The South Yorkshire branch of the Police Federation said the officer was investigating reports of an armed robbery at the time, but no further details have yet been provided.
The men and woman in custody this morning are being held on suspicion of robbery and assault offences.
A South Yorkshire Police spokeswoman said the injured officer, who was critical yesterday, is improving.
"The three still remain in police custody and no-one has yet been charged," she said.
"The officer is making a good recovery and an investigation is currently ongoing into the incident."
Anyone with information should call South Yorkshire Police on 101.