Thousands of people have gathered in Selma, Alabama, ahead of a speech by President Barack Obama at the 50th anniversary of a landmark event of the civil rights movement.

President Obama has led the tributes to Martin Luther King, exactly 50 years since his legendary "I have a dream" speech.

President Barack Obama saluted Dr Martin Luther King today as a man who “stirred our conscience” and made the Union “more perfect”.

A crowd of 300 linked arms and marched through downtown Atlanta and the neighbourhoods where Martin Luther King Jr grew up to mark the 40th anniversary of the murdered civil rights leader’s “I Have a Dream” speech.