Dutch police said Tuesday they had arrested three more teenagers and a man in connection with the shocking death of a linesman last week following an assault after a football match, bringing the total number of suspects to eight.
"Police early this morning arrested four more suspects in Amsterdam in connection with the death of Richard Nieuwenhuizen," spokesman Thomas Aling told AFP.
"Public prosecutors are to release a statement later today (Tuesday) on when they will first appear before a judge," he said.
Two 16-year-olds, a 17-year-old and a man aged 50 were arrested, Aling added.
All four are connected to, or are members of the Nieuw Sloten football club, which played against Nieuwenhuizen's Buitenboys Club in Almere, just west of Amsterdam when the December 2 beating happened.
Nieuwenhuizen, 41, officiated as linesman in the match in which his own son played and was attacked shortly after the final whistle by members of the Nieuw Sloten club. He was allegedly kicked several times in the head but got up and went home.
He became ill a few hours later and died the following day in hospital with his family at his side.
Before Tuesday's arrests, four players were detained last week in connection with the assault that has shocked the football-mad Netherlands, where some 1.2 million people out of a population of 16.5 million are members of national football federation KNVB.
On Sunday, thousands of people turned out for a silent march in Almere to pay their final tributes to Nieuwenhuizen, who was cremated at another solemn service on Monday.
The teens, who are being held at an undisclosed youth detention centre face manslaughter, assault and public violence charges.
Twenty detectives are investigating the case and more arrests could be made, Dutch police said on its website.