A murder investigation has been launched after a police officer was killed while attending a reported burglary.
Ten people have been arrested on suspicion of the murder of PC Andrew Harper, Thames Valley Police said.
The officer was attending to a scene in Berkshire and was killed near to the A4 Bath Road between Reading and Newbury at around 11.30pm on Thursday.
The incident happened at the crossroads of Ufton Lane and Lambdens Hill, near to Sulhamstead, which has since been cordoned off by police.
Deputy Chief Constable, Jason Hogg, said: "As a force we are devastated at the loss of our colleague and will all be supporting each other at this difficult time."
Detective Chief Inspector Stuart Blaik, of the Thames Valley Police Major Crime Unit, said: "This is a tragic incident, and I would like to reassure the public as well as our officers and staff that we have launched a full and thorough investigation to establish what has happened.
"We have made a total of ten arrests in connection with this incident, and those arrested are currently in police custody."
He added: "Those arrested are all male and aged between 13 and 30."
Andy Fiddler, from Thames Valley Police Federation, said: "This is totally devastating news. All our thoughts - and the thoughts of the entire police family across the UK - are with the family, friends and close colleagues of Pc Andrew Harper who died last night.
"Police officers go to work each and every day to do their duty. We are courageous, caring and compassionate. We confront danger on a daily basis. We know there is a risk when we put on the uniform but we do so as we are proud to protect the public.
"Sadly on very rare and horrendous occasions a colleague makes the ultimate sacrifice. We will ensure that heroism is never forgotten."
