The phrase "a core group of protesters" is correct and usable in written English.
It can be used to refer to a central or essential group of individuals who are actively participating in a protest or demonstration.
Example: "During the rally, a core group of protesters gathered to voice their concerns about climate change."
Alternatives: "a central group of demonstrators" or "a key group of activists".
A core group of protesters took up positions close to the encampment's kitchen area, near the center of the park.
A core group of protesters, Ismail among them, took the officers to Boulaq, a mazelike neighborhood not far from the square, where they waited out the night in a café.
The local NBC affiliate reported 23 arrests, mostly in a core group of protesters who vowed to stay in the park despite an order to leave on Thursday night.
Yet, even though the fences are due to come down next month on Phase 1 of the redesign to reveal a gleaming, newly paved central plaza with a relocated fountain, plush lawn and sculptured bushes around the fabled Washington Arch, a core group of protesters remain unconvinced and bitterly angry.
3 30 a.m.A core group of protesters locks arms in the camp's kitchen area in the center of the park, refusing to leave.
For months, a core group of protesters have maintained a constant, 24-hour presence on the mountain to disrupt construction. .
At the gates to the car park, a core group of several hundred protesters were still gathered, chanting: "Whose streets?
By Tuesday afternoon, a core group of 20 or so protesters were stationed at 50 Broadway -- an office space recently donated to the movement that, as the crisis developed, transformed into an information hub -- attempting to coordinate protesters still walking the streets and account for the night's losses.
Ms. Solanas, an unemployed online journalist, was part of the core group of protesters who in May occupied the Puerta del Sol, a public square in Madrid, the capital, touching off a nationwide protest.
The core group of protesters had worked at the giant Liaoyang Ferroalloy Plant, which was declared bankrupt last year after what workers said was the personal enrichment of its director, Fan Yicheng.
The protesters included a core group of professional musicians, who gave what amounted to a counterconcert, breaking into vocal choruses in a bid to drown out the orchestra.
