Dutch football referee death prompts minute's silence
Dutch football clubs around the country were to observe a minute's silence before their games following the fatal beating of a volunteer linesman.
Players were wearing black armbands with stadiums falling silent to pay respect to Richard Nieuwenhuizen who died on Monday in Almere.
He collapsed and fell into a coma after an attack by teenagers playing against his son's club, Buitenboys.
Four teenagers - aged between 15 and 16 - have been arrested.
Three of them have been charged with manslaughter, assault and public violence.
The death of the 41-year-old referee has shocked the country, in which football is the most popular sport, the BBC's Anna Holligan in The Hague reports.
The Dutch Football Association (KNVB) has already cancelled this weekend's 33,000 amateur fixtures and taken out full-page newspaper adverts saying "Without respect, no football".
But beyond this, on the question of what should be done to stop the violence, the KNVB admits it does not have the answers, our correspondent says.More arrests possible
In a statement, Dutch police said on Friday that a group of 20 detectives were investigating the case and that they had several dozen witnesses.
Police said they did not exclude the possibility of making further arrests and asked anyone with pictures or footage of the incident to hand it over to them.
Mr Nieuwenhuizen was attacked at the end of a junior club match on Sunday, sustaining a barrage of punches and kicks.
He collapsed at the club and died the following day.
The exact circumstances of the attack have yet to be established.