LONDON - The English Football Association has warned clubs about their players' on-field behaviour after what it calls a "scary" rise in the number of cases of referees being surrounded.

Such incidents in the top five divisions have already led to 16 FA charges against clubs, which results in a sliding scale of fines, compared with six cases in each of the previous two seasons. A further 29 warnings have also been issued to clubs this season.

"We have seen a pretty scary increase this season in the number of clubs charged with their players surrounding referees," FA chairman Greg Dyke said. "As a result we have written to the clubs in the top five divisions reminding them of the rules and their responsibilities.

"I believe it is particularly important for professional clubs to set an example so that this kind of conduct is not replicated at grassroots and youth level. The whole game needs to ensure it is addressing this issue."

Dyke was speaking after the conduct of Chelsea players in a Champions League game came under scrutiny last week. Chelsea players were criticized for surrounding the referee following an incident that saw Paris Saint-Germain striker Zlatan Ibrahimovic sent off.

That game fell under UEFA jurisdiction, but the English governing body will charge a club if "three or more players of one club approach a match official in a confrontational manner."

Chelsea and Everton earlier this month were both fined the 30,000 pounds ($44,000) for failing to control their players in a Premier League game, the standard FA penalty for topflight clubs. The FA is considering increasing the level of fines to provide a greater deterrent, particularly for repeat offenders.

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