A man and a woman are being questioned by police in connection with the killing of six men in a Co Down bar 12 years ago.
The six men were watching the Republic of Ireland playing Italy in the 1994 USA World Cup on television when they were shot.
Five other people were injured when gunmen armed with an AK47 and a Czech-made rifle sprayed bullets at customers in the Heights Bar at Loughinisland
The massacre was blamed on the UVF.
The man and woman are being questioned by police in Antrim; it is understood they were arrested in the Greater Belfast area. At least two properties were searched as part of the investigation.
Families of the dead and injured today welcomed the arrests. No one has ever been charged with the shootings ,and the families had protested to Police Ombudsman Nuala O'Loan about the lack of progress in the inquiry.
Today they issued a statement saying their referral to Ms O'Loan's office may have had some effect. "It would appear that the attention of the Police Ombudsman's office has infused fresh endeavour into what is now a 12-year-old inquiry," their statement said.