Firefighters joined their colleagues from the police at HMP Ranby where a disturbance involving prisoners is ongoing.
Shortly after 7.30pm around 15 firefighters arrived outside the prison and began putting on their full kit before walking in through the main gate.
Officers carrying shields and other equipment were also seen going into the prison earlier.
More top news
Philip Hammond's financial commitment to the NHS in this year's Budget falls short of what is needed according to hospital bosses.
As well as preparing his speech the Chancellor had spent some time preparing his gags, one of which included a prop.
An overview of the reaction to key policies in Chancellor Philip Hammond's 'forward thinking Budget'.