Police arrested six young people aged 17 to 19 from Zaanstad, Oostzaan and Wormerland on suspicion of involvement in several serious violent incidents that took place in the Zaan region last July. The incidents included explosions at homes, arson, shootings and threats. Police are still investigating the suspects’ roles and who organised the wave of violence.

Police said the incidents had a major impact on residents and involved several separate conflicts, often concerning drugs, relationship problems or business disputes. They did not rule out links between some incidents. Police also said young people had been approached through social media to carry out violence for payment and urged parents to watch for signs that children were being pressured to commit offences.