Between six and eight protesters were arrested in Berkeley, Missouri, following the fatal shooting of a black teenager by a white officer, US news reports said.
KMOV television in St Louis said the demonstrators were taken into custody yesterday after they blocked part of a busy roadway in a "die-in" protest against a string of shootings of black people in the United States by white police officers.
The St Louis Post Dispatch newspaper said about 75 people staged a second protest over police killings late yesterday, as churchgoers quietly filed into the city's cathedral for a midnight Christmas mass.
Yesterday's protest occurred nearly 24 hours after teenager Antonio Martin was killed by a police officer at a Berkeley gas station.
In the immediate aftermath, a 300-strong crowd lobbed bricks and fireworks in violent clashes with police.
Tuesday's shooting occurred not far from Ferguson, where unarmed black teenager Michael Brown was shot dead by a white officer, a mainly black town with a mostly white police force which has become 'Ground Zero' of the protests.
Demonstrations gained momentum after other African Americans - in most instances unarmed - were killed during confrontations with white police.
Officials in Berkeley have said the officer involved in the shooting appeared to have acted in self-defense.