1. Extra stewards and police

A higher security presence would certainly assist in controlling the crowd - particularly individual invaders who are intent on injuring players and officials - as in Saturday's Tri-Nations match in Durban.

2. Fines

Fining is already a major component in most countries and many sports stars champion the cause for this measure following such disturbances on the field of play.

The Australian cricket authorities, for example, have successfully introduced an automatic A$10,000 (�3,700) fine for stepping onto the pitch - and there is little doubt such punitive measures heavily discourage potential offenders.

Both streakers during Australia's recent clash against New Zealand look certain to face action.

One was charged with wilful and obscene exposure, resisting police and entering a playing field without reasonable excuse and was bailed to appear before court.

The other received on-the-spot fines for indecency and entering the playing field.

4. Fences

This measure remains one of the most contentious, particularly following England's Hillsborough tragedy in 1989 when 96 people were crushed to death.

Though widely popular at football grounds, fences remain a rarity in rugby - though there would surely be widespread support from officials around the world, should pitch invasions continue to disrupt international events.

The Rugby Football Union has successfully used plastic barriers at Twickenham but doubts remain as to whether many crowds will just see a plastic fence as a temporary hurdle on the way to the pitch.

There are also concerns about hampering the view for spectators and the concept of fans being treated like animals.

Other measures:

The introduction of police dogs at matches, riot police, removal of passports and CCTV could be considered to be some of the more extreme possibilties.

Furthermore, rugby union authorities will have to deal with the fact that it is generally deemed socially acceptable to enter the playing arena after a rugby match.