Cubans who took to the streets in protest after decades of frustration with the communist government, are feared to be imprisoned or have secretly been killed by security forces.
Three weeks after the largest anti-government demonstrations in Cuba, activist groups say more than 500 protestors are still missing.
Thousands of people across the island marched through the streets in several towns and cities on 11 July, calling for democracy and sweeping economic reform in the country amid major food and medicine shortages.
Scores of people were arrested by plain clothes police officers and many families say they still haven't heard from their loved ones or been informed of their whereabouts.
The lawyers' group Cubalex says hundreds of people, many of them teenagers, have been detained. Scores of Cubans in exile living in Miami say their relatives have not been seen by friends or family on the island since they attended a protest in Guantanamo.
They believe they were arrested shortly afterwards and are now being held at a state security prison although they do not know exactly where.