HAVANA, Sept 8 (Reuters) - Cuba's illegal opposition groups said on
                  Tuesday the ruling communist authorities had detained six dissidents in the
                  biggest crackdown on anti-government activism since Pope John Paul II's
                  visit in January.

                  But there was no confirmation from Fidel Castro's government, and it was
                  not clear if the reported arrests were temporary detentions for questioning or
                  longer-term jailings.

                  Opposition sources said the arrests -- of four women and two men -- were
                  in response to a small but rowdy protest after a recent trial of another
                  dissident which all six attended.

                  They added that it may also have been intended as a preemptive strike by
                  authorities to prevent opposition demonstrations at public festivities this
                  week in honour of two of Cuba's most revered religious icons.

                  "Whatever the reason, the message is clear: the truce is over. They have
                  decided to end the government-opposition harmony that existed since the
                  Pope's trip," said Hector Palacios, head of the small Democratic Solidarity
                  Party who was himself freed from jail in February. "It's a big blow."

                  Several moderate dissident groups named the six activists allegedly detained
                  in their homes on Monday afternoon as Vicky Ruiz Labrit of the Committee
                  of Pacifist Opposition, Miriam Garcia and Roberto de Miranda of the
                  College of Independent Teachers, Nancy de Varona of the July 13
                  Movement, Ofelia Nardo of the Confederation of Democratic Workers, and
                  Luis Lopez Prendes of the Independent Press Bureau.

                  All are small groups opposed to Castro's one-party political system, in place
                  since his 1959 revolution.

                  "There is no doubt that this is the most intensive police operation to detain
                  dissidents so far this year," the Cuban Commission for Human Rights and
                  National Reconciliation said in a statement to Reuters.

                  The six dissidents were reportedly being held at provincial police
                  headquarters in Havana.

                  "The common denominator is that they were all at the trial," added the rights
                  commission's head, Elizardo Sanchez, himself a prominent dissident who has
                  been jailed in the past.

                  He was referring to the Aug. 28 trial and sentencing to three years'
                  imprisonment of Reinaldo Alfaro Garcia on a charge of "spreading false
                  information."

                  After that trial in downtown Havana, several dozen protesters staged a brief,
                  rare demonstration outside the court building, shouting "Liberty!" and "Long
                  Live Democracy!."

                  The protesters were dispersed after they were drowned out by a larger
                  pro-government demonstration chanting "Long live Fidel!." Observers said
                  that crowd, which was mainly men and included uniformed officials, was
                  believed to be a state-organised unit known as a Rapid Response Brigade
                  intended to keep public order.

                  Diplomatic sources in Havana said on Tuesday they had heard of the six
                  reported arrests, and one added the name of Maria de los Angeles Gomez,
                  an independent journalist working illegally outside state media to the list of
                  those believed detained.

                  One diplomat said he had heard from other participants in the demonstration
                  that they had been visited and questioned by state security. Two
                  independent journalists who covered the event have alleged reprisals
                  afterward, one saying her phone was cut off and another saying he was
                  obliged to leave his temporary home in Havana.

                  Havana denies it represses freedom of speech, or holds any prisoners of
                  conscience, saying government opponents detained in jail are there on
                  legitimate charges of illegal activity including "counter-revolutionary" acts,
                  sometimes violent.

                  Opposition sources had said direct repression against them was easing since
                  the pontiff's landmark five-day visit in January and his calls then for greater
                  political freedom.

                  In Cuba, opposition and rights groups are officially outlawed and criticism of
                  the state is a potential criminal offence if deemed "enemy propaganda" or
                  "disrespect."

                  is a potential criminal offence if deemed "enemy propaganda" or
                  "disrespect."

                  Copyright 1998 Reuters Limited.