Thames Valley Police said Pc Andrew Harper died following a "serious incident" at around 11.30pm on Thursday near to the A4, Bath Road, between Reading and Newbury.
Ten males aged between 13 and 30 have been arrested and remain in custody at various police stations across the Thames Valley, a statement from the force said.
The incident happened at the crossroads of Ufton Lane and Lambdens Hill, near to the village of Sulhamstead, police said.
West Yorkshire Police officers have sent their condolences to the family of PC Harper.
On Twitter, a spokesperson for the force said: "Sending our condolences to the family of PC Harper and colleagues at Thames Valley Police after hearing of today’s terrible news."
Officers from the West Yorkshire team of the British Transport Police also shared their condolences.
The team said: "Our thoughts go out to our colleagues at Thames Valley Police and family who have lost one of their officers in the line of duty.
"The thin blue line represents another loss to the policing family who strive every hour to keep communities safe and tackle crime."
Prime Minister Boris Johnson has said he is "deeply shocked and appalled" by the death of "brave" Thames Valley police officer Andrew Harper after he was killed as he attended a reported burglary in Berkshire.