Two more people have been arrested by detectives investigating the murder of PSNI Constable Stephen Carroll on 9 March.
The men, aged 31 and 27, were detained in the Craigavon area of Co Armagh this morning.
During a search operation the PSNI have recovered two firearms, close to the scene where Constable Stephen Carroll was murdered last week.
Five other people, including a woman, are also being questioned about the police officer's murder.
Four other suspects are also in police custody in connection with shooting dead of the two British soldiers in Antrim on 7 March.
The PSNI said tonight they had been given an extra five days to question three men - aged 41, 32 and 21 - who were arrested on Saturday over the murders of two soldiers at Massereene Barracks in Antrim 48 hours before Constable Carroll's murder.
Among the detainees police have been given extra time to question is high-profile republican Colin Duffy who was detained at his Craigavon home on Saturday, not about the policeman's killing down the road but the murder of the two soldiers.
Mr Duffy, aged 41, is a former IRA prisoner who split from mainstream republicanism over the decision of Sinn Féin to support the PSNI.
He came to prominence in the 1990s after being acquitted of the IRA murder of a soldier when it emerged that a key witness was a loyalist paramilitary.
He was later arrested over the IRA murder of two Royal Ulster Constabulary officers, Roland John Graham and David Andrew Johnston, who were gunned down in 1997 as they walked the beat in Lurgan.
The case against Duffy collapsed amid huge controversy.
His solicitor, Rosemary Nelson, received threats and was later murdered in a loyalist car bomb attack at her Lurgan home in 1999.
Her death is now the subject of a high-profile public inquiry and yesterday marked the 10th anniversary of her murder.
Clinton condemns killings
US Secretary of State, Hillary Clinton, has condemned the murders of Sappers Patrick Azimkar and Mark Quinsey outside Masserene barracks and Constable Carroll in Craigavon.
She was speaking at a news conference in Washington, which was also attended by the Minister for Foreign Affairs, Micheal Martin.
Mrs Clinton said she and her husband, former president Bill Clinton, had both personally invested in the peace process, and that its success set an important example for resolving other conflicts diplomatically.
