Police in Seattle say a group of teenagers went on a week-long crime spree armed with an alarming array of illegally modified weapons, prompting fresh concern over youth violence and firearms conversion devices in the city. The incident highlights growing worries among US law enforcement about the ease with which young offenders can obtain and modify weapons to carry out multiple offences in a short period.

Details of the specific offences and arrests were limited in the available report, though it describes the teens as having wreaked havoc across the city over the course of the spree. The case adds to a wider pattern of concern in American cities regarding juvenile crime involving altered firearms and weapons capable of inflicting serious harm.