A man has been arrested in connection with a shooting that left six men dead in a pub in Loughlinisland in Co Down in 1994.
The 45-year-old man was detained in Maidstone, Kent, in connection with the 1994 Ulster Volunteer Force (UVF) atrocity.
Police are also questioning him about the attempted murder of five drinkers in the Co Down bar.
The shooting occurred as customers watched a World Cup football game. The suspect is being questioned at Antrim Police Station.
The victims were Adrian Rogan, 34, Eamon Byrne, 39, Patsy O'Hare, 35, Dan McCreanor, 59, Barney Green, 87, one of the oldest murdered during the troubles, and Malcolm Jenkinson, 54.
Their families had criticised the original police investigation for lack of progress. An alleged security force agent has been linked to the gang behind the killing.
Five people were also injured in the attack by gunmen armed with an AK47 and a Czech-made rifle.
They were in the Heights Bar on 18 June 1994 watching the Republic of Ireland defeat Italy 1-0 in the World Cup.
