text: The 25-year-old Catholic constable died when a bomb exploded under his car in Omagh on Saturday.
  A number of dignitaries including NI First Minister Peter Robinson and Deputy First Minister Martin McGuinness are at the requiem mass.
  Members of his Gaelic football club joined his police colleagues in a highly symbolic guard of honour.
  'Appalling'
  No group has claimed responsibility for the attack but dissident republicans have been blamed.
  Speaking on BBC Radio Ulster on Wednesday morning, Irish prime minister Enda Kenny strongly condemned the attack.
  "To those who think they are doing something for Ireland, this is a warped mentality," he said.
  "It is the mentality of the past, a very dark and violent past and it has no part in the future."
  He said Constable Kerr had been in the "prime of life" and it was "appalling" for his life to be taken from him.
  "It does nothing for any community in this country," he added.
  The Gaelic Athletic Association administers a number of sports including Gaelic football and hurling which are among the most popular in Ireland.
  Unprecedented
  Its joint involvement with the PSNI in the funeral service is unprecedented and has been described as highly symbolic.
  The GAA previously banned the security forces from being members but this rule was lifted after the PSNI was formed out of the Royal Ulster Constabulary in 2001.
  Dissident republicans remain opposed to the police and have repeatedly targeted officers in both gun and bomb attacks.
  Last year, Peadar Heffron, who captained the PSNI Gaelic football team, had a leg amputated after a similar booby-trap attack on his car.
  Constable Kerr was a member of the Beragh Red Knights GAA club.
  Its chairman Gerard Treacy said it was right that the GAA and the PSNI should "show solidarity with one another" at the funeral.
  "Our community has been attacked and so the community of the PSNI been attacked and today shoulder to shoulder we will stand together in solidarity and show the people of Ireland and the world that this sort of despicable action is not going to be tolerated," he said.
  'Overwhelming' messages
  NI Secretary Owen Paterson is representing the British Government at the funeral.
  It is also being attended by Irish opposition leader Micheal Martin, the Ulster Unionist Party leader Tom Elliott and several NI church leaders.
  PSNI Chief Constable Matt Baggott and his counterpart from the Irish police Martin Callinan are also present.
  Catholic primate Cardinal Sean Brady is leading the funeral mass and Father John Skinnader, a cousin of Ronan's mother Nuala, is giving the homily.
  The Irish Congress of Trade Unions has organised a lunchtime rally in Belfast on Wednesday to allow people to express their abhorrence at the killing.
  Books of condolence have been opened across Northern Ireland, while on its Facebook page the PSNI said it had been "overwhelmed by messages of sympathy and support".
  On Tuesday, the Crimestoppers charity offered a Â£50,000 reward for information leading to those responsible for the murder.
  Constable Kerr, who joined the police in May 2010, is the second officer to have been killed since the Royal Ulster Constabulary became the PSNI in 2001.
  Constable Stephen Carroll was shot dead in a gun attack in Craigavon in March 2009.
  Constable Kerr is survived by his mother, Nuala, a widow, two brothers, Cathair and Aaron and a sister, Dairine.
  1. March 2009, Massereene Barracks, County Antrim: Sappers Patrick Azimkar and Mark Quinsey are killed as they collect pizzas outside their barracks. The Real IRA said it carried out the attack
  2. March 2009, Craigavon, County Armagh: Constable Stephen Carroll, 48, is shot dead as he and police colleagues answer a call for help. The Continuity IRA says it shot the policeman
  3. February 2010, Braehead Road, near the Irish border: The naked and bound body of 31-year-old dissident republican Kieran Doherty is found close to Londonderry. The Real IRA says it abducted and murdered him
  4. April 2011, Omagh, County Tyrone: Constable Ronan Kerr is killed after a bomb explodes under his car outside his home. Dissident republicans have been blamed
  Source: BBC News reports (court cases and incidents south of the border not included)
target: The funeral for murdered PSNI officer Ronan Kerr is taking place in his home village of Beragh.