Sweden's gang wars take a toll on relatives and innocent bystanders / Masked gunman kills three people in 'brutal' Sweden attack before fleeing on scooter / At least 11 killed and many wounded in worst mass shooting in Sweden's history / Sweden shooting victims: Syria refugee Salim Iskef was killed in massacre having fled the war / Sweden shooting: 'Get out of Europe' screamed seconds before gunman committed massacre / Witnesses describe chaos and bloodshed in Sweden's worst mass shooting / Mourners pay tribute to victims of Sweden's deadliest mass shooting / Spread of gang violence wrecks Sweden's peaceful image / 'Child soldiers' and blood feuds: Sweden's out-of-control gang wars