Washington, Aug 11 (DPA) Eunice Shriver, the Kennedy sister who started a world movement for rights of the mentally handicapped, has suffered a setback since her hospitalization over the weekend.

CNN International cited a source close to the Kennedy and Shriver families as saying that relatives had been summoned back to the Cape Cod Hospital in Massachusetts where she was admitted late last week.

Shriver, 88, is the sister of the assassinated president John F Kennedy and Senator Edward 'Ted' Kennedy, who is suffering from brain cancer. Shriver apparently has suffered several strokes.

Her impetus to start a special camp in 1962 that would develop into the Special Olympics movement is credited to her older sister, Rosemary Kennedy, who was left severely retarded after part of her brain was cut away in a prefrontal lobotomy intended to correct behavioural problems.

On Friday, California Governor Arnold Schwarzenegger and his wife Maria Shriver, Eunice's daughter, were at her bedside at the hospital near the Kennedy family compound of Hyannisport.

Details of her condition on Monday were not available at the hospital, which referred callers to the Special Olympics programme office, which also could not provide an update.

Shriver, whose husband Sargent Shriver organized the US Peace Corps under his brother-in-law's administration, started a special camp at her home in suburban Maryland outside the nation's capital in 1962.