A Sinn Féin Assembly member has been arrested by police investigating the IRA bombing in Claudy in Co Derry more than 30 years ago in which nine people were killed.
Francie Brolly was one of four people detained during early morning raids by the PSNI.
Sinn Féin has condemned the arrest of Mr Brolly, saying it was politically motivated.
The Claudy attack in 1972 was a combination of three car bombs which killed six people when they exploded. Three others later died from their injuries.
A nine-year-old girl was among those who were killed.
Another man was arrested in Dungiven in Co Derry. A 50-year-old man was arrested in the Claudy area and a 58-year-old woman was arrested in Dungannon, Co Tyrone. All four are being held at Antrim Police Station.