The Swiss Guards are the pope's colourfully-dressed personal protection force.

"It was with great sadness that we heard the news of the death of our Pope Emeritus, Benedict XVI," the Pontifical Swiss Guard said.

"It was a great honour for all the guardsmen who served during his eight years as head of the Catholic Church to be able to serve him. Requiem."

The Swiss Guards were created in 1506 by pope Julius II.

They are a popular tourist magnet at the Vatican, with their showy yellow, red and blue uniforms, halberds -- an axe-like weapon -- and metal helmets with ostrich plumage.

Swiss Guards must all be men between 19 and 30 years old and at least 1.74 metres (5.7 feet) tall. They must be practising Roman Catholics, Swiss, and unmarried at the time of signing up.

The 135 guards commit to safeguarding the pope for at least 26 months.

Former pope Benedict died at the age of 95, almost a decade after he became the first pontiff to resign in six centuries.