Officers nationwide have offered cover to colleagues in Greater Manchester Police so they can attend the funerals of the two killed PCs.
Manchester's police chief said he expected "developments" in the next 24 hours over possible charges relating to the deaths of two officers.
Over 50,000 tributes have been posted to Greater Manchester Police's online book of condolence to the two killed officers and Facebook page.
Greater Manchester Police claimed today that gun crime there has fallen significantly over the past ten years.
But there is still violence involving ever more vicious attacks and ever more dangerous weapons and the police have warned some people that their lives could be in danger.
ITV News UK Editor Lucy Manning spoke to Joe Pennington who was warned by police that his boxing club was at risk of violence.
The second man arrested in connection with the killings of two police officers is 28-year-old Stephen Garvey.
Garvey was arrested on suspicion of conspiracy to commit murder.
Greater Manchester Police Chief Constable Sir Peter Fahy said he "anticipated developments in the next 24 hours" over possible charges relating to the killings of PC Nicola Hughes and PC Fiona Bone.
Greater Manchester Police Chief Constable Sir Peter Fahy said the families of killed officers PC Fiona Bone and PC Nicola Hughes were "overwhelmed" by the support they had received from the public.
Greater Manchester Police tweeted:
Manchester City FC flies its flag at half mast in memory of PC Fiona Bone and PC Nicola Hughes http://t.co/fZbkDhQO
Greater Manchester Police have announced that Chief Constable Sir Peter Fahy and Chief Superintendent Nick Adderley, divisional commander for Tameside, will be laying flowers at the scene in Hattersley at around 3.30pm today.