Queen Mother Ingrid of Denmark has died at the age of 90.

A statement issued by the royal palace said Queen Ingrid had passed away quietly at Fredensborg Castle, north of Copenhagen, at 1627(1527 GMT).

Her death was announced on national radio and the two main television stations interrupted programmes to report the news.

Her three daughters, Queen Margrethe, Princess Benedikte and the former Queen Anne-Marie of Greece, and 10 grandchildren were at her bedside when she died.

Once news of the Queen Mother's death had been announced, thousands of Danes gathered outside the Amalienborg palace, her official residence.

They laid bouquets of flowers, lit candles and sang hymns in memory of what one mourner called "a woman full of wisdom and good sense".

Oldest royal house

Ingrid Victoria Sofia Louise Margaretha was born in Stockholm, Sweden in 1910.

She was a great-granddaughter of England's former Queen Victoria and an aunt of Sweden's current King Carl XVI Gustaf.

She entered Europe's oldest royal house at the age of 25 after marrying the then Crown Prince Frederik of Denmark.

Queen Ingrid was believed to have played a decisive role behind the scenes in 1953 when the Danish constitution was amended to allow women to accede to the throne.

Her daughter Margrethe became queen in 1972, on the death of her husband, King Frederik IX.

Queen Ingrid remained active into old age as patron of about 40 social welfare and aid organisations.