Amsterdam police have arrested a fourth boy in their investigation into the death of an amateur football linesman, who was attacked by players after a match on Sunday.

The boy is 16 and comes from Amsterdam. More arrests have not been ruled out, police say. Three boys, aged 15, 15 and 16 were arrested on Monday morning and remanded in custody for a further 14 days by judges on Thursday.
The 41-year-old linesman collapsed several hours after being attacked after a game between the B1 of Amsterdam club Nieuw Sloten and the B3 of Almere side Buitenboys. He died in hospital on Monday.
Police are appealing for more eyewitnesses to come forward and for people with photographs to hand them over. The Telegraaf newspaper published a photograph on its front page on Monday which it says shows Richard Nieuwenhuizen being kicked as others look on.
Ethnicity
Meanwhile, the Volkskrant newspaper is carrying an article asking if the youths who are allegedly responsible for the attack are ‘boys or Moroccans’.
There has been no official mention of the suspects’ ethnicity, who are described by the public prosecution department as Dutch, the paper points out.
Football club Nieuw Sloten is a mixed club, and about half its members have an ethnic minority background, the Parool reported on Thursday.
Dutch
RTL news chief Pieter Klein told the paper his reporters had produced an in-depth report on the case ‘but do not say the team is largely from an ethnic minority’. ‘After all, what does that actually mean?’ Klein is quoted as saying.
Meanwhile, Achmed Baadoud, chairman of Amsterdam borough council Nieuw West, told free newspaper Metro that bad parenting is to blame for the violence in amateur football.
‘Many parents tell me they were hit at home and they don’t know how to punish their own children,’ Baadoud told the paper. He wants the Dutch football organisation to help referees and linesmen deal with aggression while at the same time find ways to help parents deal with their teenage offspring.
Cruijff
Former Dutch international Johan Cruijff told Nos television parents are largely to blame for football-related violence.
‘If you look at the way some parents behave during matches for children aged six to 11, it is a complete scandal,’ Cruijff said. ‘You need to start by instilling standards, and removing parents [who cause trouble],’ he said.