The elite stars were left open-mouthed at the melee just feet (a couple of metres) away as they lined up to be photographed.

Several photographers jostling for position suddenly started shouting and shoving each other, forcing officials to intervene. Order was quickly restored.

China has become increasingly concerned about standards of behaviour ahead of the 2008 Olympics and has launched a series of initiatives to promote good manners.

Basketball superstar Yao Ming last month urged the public to be more courteous and in Beijing, buses are fitted with cameras to monitor passengers' manners.

The world's top eight tennis players are contesting the Masters Cup, which starts on Sunday.