Washington - 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 reported Monday.

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. The intention was to to "explore" the capabilities of "adults with intellectual disabilities" for sports and physical activities, according to the Special Olympics' website.

In 1968, just weeks after the assassination of another brother, Robert, who was running for the Democratic presidential nomination, Shriver launched the first International Special Olympics Summer Games.

They attracted 1,000 individuals with intellectual disabilities from 26 US states and Canada to compete in track and field and swimming.

By 2008, the Special Olympics celebrated its 40th anniversary, drawing nearly 3 million athletes from more than 180 countries to the event that followed the regular Olympic Games in Beijing.

"The Special Olympics movement is saddened to hear that our founder, Eunice Kennedy Shriver, is hospitalized. Our thoughts and prayers are with Mrs Shriver and her family at this time," organization President Brady Lum said in a statement last week.

Shriver's idea was to use "sports as the catalyst for respect, acceptance and inclusion," Lum noted.

Shriver's influence on her brother, the former president, is credited with the push in 1963 to pass the first law in US history to protect and support the rights of the mentally disabled.

Shriver's daughter, Maria, was a well-known television reporter who married the Republican Schwarzenegger. Eunice Shriver campaigned for her son-in-law in the gubernatorial race.

Although Rosemary Kennedy's history of mental illness is unclear, her father, Joseph Kennedy, sent her for the relatively new and since discontinued procedure of a prefrontal lobotomy when she was only 23, in 1941. The cutting away of part of her brain reduced her to severe retardation.

Rosemary was kept in an institution and out of the public eye until her situation became public in 1960, as her brother John was running for president. She died in 2005 at age 86.(dpa)