Bosses at security firm G4S, which runs HMP Oakwood in South Staffordshire, have put contingency plans in force as a rooftop protest continues at the prison.
A spokesman confirmed six prisoners were involved in the incident.
We can confirm that an incident involving six prisoners is taking place at HMP Oakwood.
The Ministry of Justice has been alerted and our normal contingency plans have been enacted.
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Feeling less cold than recent days with winds easing and some long sunny periods. Most areas will be dry throughout.
A cold start with some icy patches. Largely dry and sunny through the day, with any showers soon dying out and winds easing too.
Scattered wintry showers during the evening will become fewer and further between overnight, with westerly winds tending to ease.