Campaigners in London have marked the 31st anniversary of Bloody Sunday with a demonstration at Downing Street.
Protesters have sent a letter to Tony Blair demanding the disclosure of British army film footage taken from a helicopter on the day and over 1,000 photographs of events in Derry.
They claim Britain's Ministry of Defence has withheld the material from the Saville Inquiry into the killing by paratroopers of 13 unarmed civilians in January 1972.
The letter handed in at Downing Street this afternoon asks the British Prime Minister to direct the Ministry of Defence to hand the material over to the inquiry and relatives of the victims or explain what has become of the evidence.
Meanwhile the Saville Inquiry in London is not sitting today as a mark of respect to those who died.
