Police in Massachusetts have reported that a group of heavily-armed men dressed in military-style uniforms refused to put down their weapons and comply with officers following a traffic stop.
Police noticed two cars pulled over on the highway with their hazard lights on after they had apparently run out of fuel.
According to the authorities, the men claimed to belong a group that does not recognise American laws - they then left their vehicles and fled into woods near Interstate Highway 95. The standoff shut down part of the highway in both directions, creating heavy traffic just before the US celebrated Independence Day on 4 July.
Residents in the area where the incident took place were asked to stay at home.
Police eventually managed to arrest all nine suspects without shots being fired. They have been taken into custody.
Officers said they will conduct sweeps of the two vehicles and nearby woods.