Gerry Adams has apologised for using the N-word in a tweet about film Django Unchained but defended the "context and substance" of the point he was making.

The Sinn Fein president said it was "inappropriate" to have used the word on his Twitter account after watching the Quentin Tarantino slavery film on Sunday night.

He tweeted: "Watching Django Unchained - A Ballymurphy N****r!" Although the tweet was removed swiftly it provoked a furious reaction.

Mr Adams said he was trying to make "a parallel between the plight of people here in Ireland the struggle of people from African-American extraction".

He added the Irish civil-rights campaign, of which he has played a major role, was based broadly on the American civil rights campaign.