PORTLAND, Ore. (AP) — Portland police detained a crowd of at least 100 protesters Friday night at a demonstration, halting the march minutes after it started. The Oregonian/Oregonlive.com said the mass detainment shortly after 9 p.m in the Pearl District appeared to an example of kettling, a police tactic of surrounding a crowd and containing people within a perimeter. In a tweet and at the scene, police said they were detaining everyone within the boundary for the “investigation of a crime.” Portland has been the site of frequent protests, many involving violent clashes between officers and demonstrators, ever since the police killing of George Floyd in Minneapolis in May. Over the summer, there were demonstrations for more than 100 straight days.