Her speech followed a week of claims of racism against Commonwealth soldiers in the British military and amid violence in Zimbabwe, where unrest continues four years after it pulled out of the club of former British colonies.

Queen Elizabeth, the head of the Commonwealth, called for diversity to be viewed as a source for celebration rather than conflict.

"By respecting the difference and promoting understanding, the future will be a better one for us all," she told a special multi-faith service at London's Westminster Abbey to mark Commonwealth Day.

"In today's difficult and sometimes divided world, I believe that it is more important than ever to keep trying to respect and understand each other better," she told the 2000-strong congregation.

"Let us as individuals actively seek out the views of others; let us make the best use of what our beliefs and history teach us; let us have open minds and hearts; and let us, like the Commonwealth, find our diversity a cause for celebration and a source for strength and unity."

Commonwealth Day celebrates the voluntary Commonwealth of Nations, set up in 1926 and reformed in 1949.