The phrase "a group of hostile" is correct and usable in written English.
It can be used to describe a collection of individuals or entities that exhibit hostility or aggression towards something or someone.
Example: "The town was on high alert due to a group of hostile individuals gathering near the border."
Alternatives: "a band of aggressors" or "a faction of adversaries".
She added, "Everyone had a 'them' " -- a group of hostile former competitors bent on subversion.
"A chilling spectacle … right out of the dark ages," writes Andrea Monti in Monday's Gazzetta dello Sport, seeking to convey the mood from a match at which the players themselves were effectively made hostage to a group of hostile Ultras.
Almost immediately I was jumped on by a group of hostile members who thought that I couldn't be a real, bonafide feminist because I didn't believe aligning feminism with a social revolution and trade union discussion was the way to go.
No one is certain who carried out the attacks, but the Americans were blamed for having allowed them to happen, and when troops attempted to come into Kadhimiya to help they were turned back by a group of hostile young men who hurled abuse and rocks at them.
A group of hostile students approached, taunted her, and then humiliated her by dripping soda on her head.
He travels to a nameless rural village in an unspecified part of Europe, where he encounters a group of hostile villagers who pledge their lives to Los Illuminados ("The Enlightened Ones" in Spanish), the cult that kidnapped Ashley.
Val and her "mampy squad" were a progression from "Scotland Yardie" – a group of oppressively hostile women flown in from Jamaica to police the streets of Harlesden.
When the Senate on the motion of his cousin Scipio Aemilianus, who later finished the war renounced the peace, Tiberius felt aggrieved; he joined a group of senior senators hostile to Aemilianus and with ideas on reform.
G.E. has done its best to feed these anxieties... Mentions that a group of vocal and hostile counter-demonstrators at the Scenic Hudson rally adamantly denied having anything to with G.E. even after it was pointed out to them that a set of tiny letters on their signs, which, when viewed from up close, clearly read, "General Electric Corporation".
A small but vocal group of hostile Ulster loyalist demonstrators were standing outside, blocking the station's heavily fortified gates, preparing to hurl abuse when he emerged.
With little more to announce to a group of about 100 sometimes hostile journalists, Blatter, 77, answered questions in three languages, stonewalled others and waved away at least one with a flick of his hand.
