LONDON (AP) — Thousands are expected to gather Friday in southwest England for a climate march to be joined by activist Greta Thunberg.

Local police have expressed concern about the march through the city of Bristol amid worries that the event’s popularity could lead to risks to protesters. Police warned that demonstrators might be hurt by "tripping, falling or being crushed by the crowds."

In a response posted on Twitter, the protest organizers, Bristol Youth Strike 4 Climate, said they had "no time for being patronised.”

They have arranged for festival barriers, more than 80 stewards and a safe zone for young children.

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