At least 18 jailed Cuban dissidents have been transferred to a prison hospital in Havana amid speculation they may be released.

Relatives say activist physician Oscar Elias Biscet and opposition politician Hector Palacios were among those transferred.

The move comes after authorities this week released five of 75 pro-democracy activists jailed last year in a crackdown on dissidents.

Each of the five had been transferred to the same prison hospital for checkups before their health-related releases.

Among those freed were well-known dissident writer and poet Raul Rivero, opposition politician Osvaldo Alfonso Valdes and economist and journalist Oscar Espinoso Chepe.

They were sentenced last year to lengthy jail terms on charges they conspired with the United States to overthrow President Fidel Castro.

Analysts say Cuba released the dissidents, rather than having them possibly die in prison.

Some information for this story provided by AP and AFP.