The pope opened his visit Monday with a public mass in Santiago de Cuba. Amnesty International said dozens of critics of the Cuban government were detained, while state security officers surrounded the homes of others to keep them from attending.
The Cuban Commission on Human Rights and National Reconciliation and other groups lost telephone service, starting Monday.
"The communications' blockade and the detention of more than 150 political opponents is yet another example of how Cuban authorities completely disregard human rights," Javier Zuniga of Amnesty International said. "Authorities must immediately stop harassing activists, and ensure everyone in Cuba is free to voice their opinions and carry out legitimate activities."
The pope, who presided over another mass in Havana Wednesday, was to leave Cuba later in the day. The government began releasing detainees after his private meeting with former President Fidel Castro, The Miami Herald said.