The England rugby union team have been fined for six of their players crossing the halfway line during New Zealand's pre-match haka during the world cup semi-final in Japan.

Opponents must stay in their own half while New Zealand perform their traditional war dance, a feature of international matches for more than a century.

Instead of facing the haka shoulder-to-shoulder, the England team lined up in an inverted V, with the six players at the two closest ends of the formation standing over the halfway line.

World Rugby said England had breached tournament rules "relating to cultural challenges." 

New Zealand's coach Steve Hansen said he thought England's idea "was fantastic... the haka requires a response. I thought it was brilliant and quite imaginative too." The fine was for crossing the halfway line rather than the V formation, Hansen added. 

England coach Eddie Jones came up with the haka response plan. Captain Owen Farrell said: "We wanted not to just stand there and let them come at us."

The size of the fine is not known yet but in the 2011 Rugby World Cup, France were fined $3,200 after they formed an arrowhead formation and marched towards the haka before that year's world cup final.

England won Saturday's match 19-7 and are due to play South Africa in the final on 2 November.