A crackdown on Cuban dissidents and independent journalists is intensifying on the communist-run island. The government of President Fidel Castro has arrested dozens of so-called "subversives" and "counter-revolutionaries" over the last three days.

Noted Cuban dissident Marta Beatriz Roque is among the latest to be detained, in what has become one of the largest sweeps against the government's perceived enemies in recent years. Ms. Roque, who heads an umbrella group of dissident organizations, was arrested while on a hunger strike to press for the release of political prisoners on the island. Her relatives are quoted as saying police seized a computer as well as books and papers from the home of Ms. Roque, who was jailed for three years in the late 1990s on charges of sedition.

The Castro government accuses dissidents and a small band of independent journalists of serving as pawns of the United States. The U.S. Interests Section in Havana openly backs those who advocate political reform on the island.

The crackdown has been denounced by U.S. officials, as well as international human rights groups and journalistic organizations. Before the current wave of arrests, Cuba's jails were believed to hold several hundred political prisoners.

Meanwhile, the Castro government is calling for the immediate return of an airliner that was hijacked and flown to Key West, Florida late Wednesday. Cuba says the hijackers, passengers and crewmembers, at least 35, must also be repatriated. U.S. authorities say six hijackers face air piracy charges in the United States, but that many of the passengers and crew have expressed a desire to return to Cuba.