Aug. 20 (UPI) — Newly appointed U.S. Assistant Secretary of State for Western Hemisphere Affairs Juan Pablo Segura on Thursday demanded the release of Cuban rapper Maykel “Osorbo” Castillo Pérez, who turned 43 while serving a nine-year prison sentence in Cuba.

“Today, Maykel ‘Osorbo’ Castillo Pérez should be celebrating his birthday with his family, not unjustly imprisoned in a Cuban prison,” Segura wrote on his office’s official X account.

“We stand with Maykel and demand the release of all political prisoners who have bravely confronted the corruption and injustice of the Cuban communist regime,” Segura added, using the hashtag #FreeMaykel.

The demand comes as Cuba holds 1,327 political prisoners and prisoners of conscience, according to the Prisoners Defenders registry, as of July 31.

The Madrid-based organization added 36 new cases during July, 15 of them connected to protests. The documented cases include Alex Javier Hernández González, 13, who was detained in Havana after demonstrations over power outages.

According to Prisoners Defenders, the teenager’s mother said four police officers struck him in the head, neck and back before taking him to a police station. The organization said he was detained without a court order and remains held at a juvenile detention center.

The report also documented the arrests of two artists who participated in a protest against the power outages, as well as cases involving activists, journalists and content creators prosecuted for reporting on the crisis or sharing critical messages.

It also said courts upheld sentences of 14 and 13 years against two people who had initially been acquitted because of insufficient evidence.

The Cuban government rejects the existence of political prisoners and maintains that people described as such were convicted of offenses under national law.

Castillo Pérez was detained on May 18, 2021, and convicted in June 2022. The Cuban Attorney General’s Office said he received a nine-year sentence for contempt, assault, public disorder and defamation of institutions and organizations, heroes and martyrs.

Prosecutors said the musician shared manipulated images to offend Cuban authorities, participated in a confrontation with police officers and helped provoke a gathering that occupied a public roadway.

International organizations, however, consider his detention arbitrary.

The Inter-American Commission on Human Rights concluded in a report published in July that the Cuban state violated, among other rights, his personal liberty, freedom of artistic expression and judicial guarantees. The commission recommended overturning his conviction, investigating the violations and providing reparations to the artist.

Amnesty International also recognizes Castillo Pérez as a prisoner of conscience and has called for his immediate and unconditional release.

Castillo Pérez is a member of the San Isidro Movement and a co-writer and performer of “Patria y Vida,” which became an anthem of protests against the Cuban government and won Latin Grammys for song of the year and best urban song in 2021.