The phrase "a violent group" is correct and usable in written English.
It can be used to describe a collective of individuals who engage in or promote violence.
Example: "The authorities are concerned about the activities of a violent group operating in the area."
Alternatives: "an aggressive faction" or "a militant organization".
The existence of a deadly cell of neo-Nazis shocked German society when it came to light a year ago, raising questions about how a violent group of renegades could operate undetected for so long and why the police had persisted in searching for ties to Turkish organized crime instead of violent racists.
"He was a young recruit of a violent group called Abu Sayyaf.
The government views the Karamojong as a violent group of cattle rustlers.
The most pressing question remains how such a violent group could have gone unnoticed by police and intelligence officials.
"He clothes himself in religiosity, but there is a violent group behind him who allow him to take his actions".
His decision to join a violent group responsible for beheadings and forced amputations was especially bewildering to family and friends.
"He's a member of a horribly violent group," she said of Boman.
Another factor was a death threat from the Jewish Defense League, a militant, violent group.
The man told agents that he was a Honduran citizen who had traveled with the caravan, and that he was an active gang member with MS-13, a notoriously violent group.
In the districts around the city, a particularly violent group of young Taliban commanders terrorise locals and exert parallel power.
Maduro, appearing on state television, has instead placed the blame on Washington, claiming the attack was carried out by a "small, violent group, financed by the US government".
