A series of rallies have taken place across Northern Ireland as people showed their anger at the murders of two soldiers and a policeman. Thousands of people attended.
Silent protests took place in Belfast, Lisburn, Newry, Downpatrick and Londonderry.
A peace vigil is also to be held in Craigavon, County Armagh, near the site where Constable Stephen Paul Carroll, 48, was shot dead on Monday.
The BBC reports two people are being questioned over the killing.
Prime Minister Gordon Brown has sent words of support to MPs who held a vigil outside Westminster in support of the peace rallies held in Northern Ireland.
On Saturday, Mark Quinsey, 23, from Birmingham, and Patrick Azimkar, 21, from London, were shot at Massereene Army base, Antrim, at about 2120 GMT.
The Real IRA said they killed them. Four men were also wounded in the attack. One of them is in a critical condition and another is seriously ill.
Police chiefs from Northern Ireland and the Irish Republic are to meet on Thursday to assess the security threat posed by dissident republicans.