Tens of thousands of Argentines march in Buenos Aires to mark 49 years since the coup d'etat that gave rise to a brutal military dictatorship blamed for the disappearance of some 30,000 people. Holding aloft torches and photos of their missing loved ones, the demonstrators gather under the banner of "Memory, Truth and Justice" on Argentina's National Day of Remembrance. As participants clamored for truth, the government announced it would declassify intelligence files on the actions of the armed forces during the dictatorship's 1976-83 reign. IMAGES AND SOUNDBITES