An ongoing disturbance is taking place at HMP Ranby in Nottinghamshire after 120 inmates refused to return to their cells.
The Prison Officers' Association confirmed the "serious incident" began at 12.30pm with minor damage caused but no injuries to staff or prisoners.
More top news
Once a year W11 comes alive with the colour of carnival. Everything you need to know about getting around and what to see in Notting Hill.
People should only be allowed to move freely within the EU if they have a job waiting for them, the Home Secretary has said.
A 62-year-old woman has been found alive more than a week after she vanished while on a hiking trip.