A young woman sits on a staircase as two school girls stand next to a ballot box at a polling station at a school during the municipal elections in Havana April 19, 2015. The writing on the poster showing Cuba's former President Fidel Castro (L) and his brother Cuba's President Raul Castro reads, “The revolution, powerful and victorious, goes ahead”. (Photo by Reuters/Stringer)

Under a picture of Cuba's leader Fidel Castro, a voter presents his identification papers before voting at a polling station in Havana, Cuba, Sunday, April 19, 2015. Cuba held its first local elections since a historic thaw in relations with the United States with an unusual wrinkle in the single-party system: two of the 27,000 candidates openly oppose the government. (Photo by Ramon Espinosa/AP Photo)

A woman holds her papers to be checked by electoral officials before casting her ballot during Cuba's municipal elections outside a polling station in Havana, Cuba, Sunday, April 19, 2015. (Photo by Desmond Boylan/AP Photo)

School children look at the list of voters at a polling station in Havana, Cuba, Sunday, April 19, 2015. (Photo by Ramon Espinosa/AP Photo)

Caretaker Adriana Haedo, 40, sits beside a poster of former Cuban leader Fidel Castro (L) and his brother President Raul Castro at a polling station to be used for the municipal elections, in Havana April 18, 2015. (Photo by Alexandre Meneghini/Reuters)

A woman looks through the window of a polling station to be used for the municipal elections in Havana, April 18, 2015. (Photo by Alexandre Meneghini/Reuters)

Schoolboys stand next to the ballot box at a polling station in Havana April 19, 2015. (Photo by Enrique de la Osa/Reuters)

Cuban ward delegate Hildebrando Chaviano Montes prepares to cast his vote at a polling station in Havana, April 19, 2015. In a rare challenge to Cuba's political system from within, two government opponents are on the ballot for upcoming elections, only to find that officials have altered their biographies to portray them as dangers to the revolution. Chaviano, 65, and Yuniel Lopez, 26, are running for municipal assembly in Havana on April 19 after winning endorsement from their neighbours in a show-of-hands vote at public meetings last month. (Photo by Alexandre Meneghini/Reuters)

Ten-year-old schoolgirls Claudia Fuentes (R) and Laura Gonzales chat as an elector casts her vote at a poling station in Havana, April 19, 2015. (Photo by Alexandre Meneghini/Reuters)

A youth (L), who had just cast her vote for the first time after turning 16, receives a postcard from an official with a picture of Cuba's former President Fidel Castro (R) and revolutionary hero Camilo Cienfuegos at a polling station in a school in Havana April 19, 2015. (Photo by Reuters/Stringer)

A woman walks out of a voting booth to cast her vote at a polling station at a school in Havana April 19, 2015. (Photo by Reuters/Stringer)

Women walk to the ballot box to cast their votes at a polling station set up at a central office of the Committees for the Defence of the Revolution (CDR) for this district in Havana April 19, 2015. The CDRs, created by former Cuban leader Fidel Castro, are assigned to every block of houses in Cuba, to provide medical assistance if needed, and to monitor people's movements and activities in each neighbourhood. (Photo by Reuters/Stringer)

A woman marks her ballot at a polling station at a school in Havana April 19, 2015. The municipal elections take place in Cuba today. The sign reads “Election for municipal delegates. Vote for 2015 Cuba”. (Photo by Reuters/Stringer)

A polling station is seen at dawn before opening for municipal elections in Havana April 19, 2015. (Photo by Alexandre Meneghini/Reuters)

Election officials work at a polling station in Havana April 19, 2015. (Photo by Alexandre Meneghini/Reuters)

A woman casts her vote beside a picture of former Cuban leader Fidel Castro (L), and his brother, President Raul Castro at a polling station in Havana April 19, 2015. The text on the picture reads, “The thriving and victorious revolution moves forward”. (Photo by Alexandre Meneghini/Reuters)

Election officials get ready to open a polling station in Havana April 19, 2015. (Photo by Alexandre Meneghini/Reuters)

Dissident and candidate Hildebrando Chaviano walks beside a portrait of revolutionary leader Che Guevara before casting his ballot during Cuba's municipal elections at a polling station in Havana, Cuba, Sunday, April 19, 2015. (Photo by Desmond Boylan/AP Photo)

Schoolboys salute as a man casts his vote at a polling station in Havana April 19, 2015. (Photo by Reuters/Stringer)

Cuba's First Vice-President Miguel Diaz Canel (red shirt), walks with his wife Lis Cuesta (partially obscured) and bodyguards after casting his vote at a polling station in Havana April 19, 2015. (Photo by Reuters/Stringer)

Officials sing Cuba's national anthem before opening a polling station in Havana April 19, 2015. (Photo by Reuters/Stringer)

School girls stand next to a ballot box at a polling station in Havana April 19, 2015. (Photo by Reuters/Stringer)

School girls salute as a woman casts her vote at a polling station in Havana April 19, 2015. (Photo by Alexandre Meneghini/Reuters)

People stand at the entrance of a polling station in Havana, April 19, 2015. (Photo by Alexandre Meneghini/Reuters)

School children salute as a woman casts her ballot during Cuba's municipal elections at a polling station in Havana, Cuba, Sunday, April 19, 2015. (Photo by Desmond Boylan/AP Photo)