Washington, Aug 12: Eunice Kennedy Shriver, a younger sister of late US President John F Kennedy and known for her work on behalf of people with mental disabilities, died on Tuesday morning, media reports said citing the Kennedy family. She was 88.

The reports said Shriver died around 2 a.m. in hospital in Cape Cod, Massachusetts, where she had been in intensive care for the past week.

Founder of the Special Olympics to allow people with mental disabilities to compete in sports - her work was in part inspired by the struggles of her mentally disabled sister, Rosemary - Eunice Shriver was from one of America's most prominent political families.

She was the fifth of nine children of Joseph P. Kennedy Sr. and Rose Kennedy, with her siblings including the late president Kennedy and late senator Robert Kennedy - both were assassinated in the 1960s - as well as current Massachusetts Senator Edward M. Kennedy.

She was also the mother-in-law of current California Governor Arnold Schwarzenegger.

Eunice Shriver is survived by her husband R. Sargent Shriver and their five children. A statement by the Special Olympics said that her husband, five children and their spouses, as well as her 19 grandchildren were with her when she died.

"We are tremendously grateful for the extreme outpouring of support and prayer from the public as we honour our beloved founder," Special Olympics President and Chief Operation Officer Brady Lum said Tuesday in a statement.

"Today we celebrate the life of a woman who had the vision to create our movement. It is an enormous loss, but I know we can rest assured that her legacy will live on through her family, friends, and the millions of people around the world who she touched and transformed," he added."