NBC新闻:波特兰抗议者与特工起冲突

Overnight in Portland protesters launch mortar-style fireworks at federal agents. The steel barrier that encases the federal courthouse between them provoking this response. What started two months ago as protests against police brutality has now become a nightly ritual. They started gassing us so we came back with respirators. They started shooting us. So we came back with vests. Who's escalating this? It's not us. 

State officials say the agents are not welcome but the president insists they're here to protect federal property. In nearby Seattle on Saturday a show of solidarity with portland's protesters devolved from peaceful into what police call a riot. Federal agents stayed out of sight. President says they're in Seattle for emergencies only. Here at the police precinct in downtown Seattle they're bracing for the possibility of more violence. You can see the windows are covered in plywood. They just set up the cement barricade, each block weighs 4 000 pounds. In Los Angeles protesters and police clashed outside the federal courthouse. And in Louisville opposing armed militia groups faced off at a demonstration. Now officials and protesters are preparing for what tonight may bring.