Elizardo Sanchez, who monitors human rights on the island and acts as a de facto spokesman for the opposition, said he could not confirm any detentions because his mobile phone hadn't worked since shortly after the pope arrived on Monday. It was an experience shared by many other islanders and foreign journalists who could not make calls on jammed lines.

John Paul's shadow has loomed large over the trip, especially his remarks upon arrival at Havana's airport in 1998 saying Cuba should "open itself up to the world, and may the world open itself up to Cuba."

Benedict took that famous exhortation for openness one step further Wednesday by saying "Cuba and the world need change."

A huge poster of Cuba's patron saint, the Virgin of Charity of Cobre, covered the facade of one of the buildings facing the plaza near Che. The icon has been the spiritual focus of Benedict's three-day trip, timed to coincide with the 400th anniversary of the appearance of the diminutive statue.

Benedict visited the statue in a sanctuary near the eastern city of Santiago on Tuesday morning and prayed to her for greater freedom and renewal for all Cubans -- another gentle nudge to the government to continue opening itself up to greater reforms.

A top official in Havana quickly responded: "In Cuba, there will not be political reform," said Marino Murillo, Cuba's economic czar.

During a nearly hour-long meeting Tuesday with Raul Castro -- twice the normal length of papal audiences with heads of state -- Benedict asked that the government declare a holiday for Good Friday, when Catholics commemorate the death of Christ.

The request, like so much of this trip, was a follow-up of sorts to Cuba's decision to declare Christmas a national holiday in honor of John Paul's 1998 visit. Cubans hadn't had Christmas off for nearly 30 years.

The government didn't give an immediate response.

The date is not a holiday in the United States or much of Europe, including Italy or devoutly Catholic Poland, but is in many Latin American countries.