Image caption Dale Cregan, 29, has been charged with four murders

The killings of two police officers "shocked and appalled the country", the Chief Crown Prosecutor for the North-West of England has said.

Nazir Afzal commented as he authorised police to charge Dale Cregan, 29, with the murders of PC Fiona Bone, 32, and her colleague PC Nicola Hughes, 23.

They suffered fatal injuries in a gun and grenade attack in Mottram, Tameside, on Tuesday.

Mr Cregan is also accused of murdering Mark Short and his father David.

He also faces four charges of attempted murder.

Mark Short, 23, died from a gunshot wound to the neck after a shooting in the Cotton Tree Inn in Droylsden, Greater Manchester, on 25 May.

His father David, 46, was found dead at a house in Folkestone Road, East, Clayton, Greater Manchester, on 10 August after police were called following reports of gunshots.

Three of the four attempted murder charges relate to the pub shooting. The fourth relates to the attack in Clayton.

Mr Afzal said: "The tragic events this week in which Police Constables Fiona Bone and Nicola Hughes lost their lives in the line of duty have shocked and appalled the whole country."

Sir Peter Fahy, Chief Constable of Greater Manchester, described the inquiry as a "complex investigation".

He renewed police appeals for anyone with information to contact detectives, calling on them "to look at their conscience and come forward".

Media playback is unsupported on your device Media caption Chief Crown Prosecutor for the North-West of England, Nazir Afzal, announces the charges

On Thursday, Sir Peter laid flowers at the scene in Mottram where the officers were fatally injured.

He paid tribute to them calling them "two wonderful human beings, two very dedicated officers" who left behind "two very proud families obviously devastated by their loss".

He added the families had asked him to pass on their "huge appreciation" for the massive show of public support.

An online campaign has been started by police officers around the country offering to work for GMP on the day of the dead officers' funerals to allow all their GMP colleagues to attend the services.

On Wednesday, GMP announced more than 25,000 people had left condolence messages on their website.

A 22-year-old man has been bailed by Merseyside Police pending further inquiries, after an offensive Facebook page went online within hours of the deaths of the PCs.