Queen Elizabeth II opened the 54-nation Commonwealth Heads of Government Meeting on Friday where issues from human rights to succession to the British throne will be discussed. Leaders were greeted with a traditional indigenous cleansing ceremony at the Perth Convention Centre by elders from the Noongar Aboriginal tribe ahead of a dance performance amid tight security. The monarch said she was delighted to be in Perth \"for a meeting that promises to bring new vibrancy to the Commonwealth\". \"Ladies and gentlemen, it gives me great pleasure to declare open this 21st meeting of the Commonwealth Heads of Government Meeting,\" she added. Most Commonwealth leaders are attending, although Indian Prime Minister Manmohan Singh pulled out without giving a reason while Britain\'s David Cameron is arriving later Friday after attending the eurozone debt crisis talks.