Brook House was opened in March and can house 426 people
A fire was started and "disorder" broke out at a wing of an immigration removal centre near Gatwick Airport, Sussex police said.
Officers said there were reports of minor damage and a blaze in the exercise yard at Brook House, which houses 312 people awaiting deportation.
No-one is believed to be hurt and the fire is said to have burnt itself out.
The force said "disorder" involving 30 detainees started at about 2250 BST and was confined to one wing.
Officers were called in to support security firm G4S.
G4S, with the help of HM Prison Service, currently manages the welfare of detainees inside the centre, the police said.
Ch Insp Ed Henriet, of Gatwick Police, said: "Sussex Police is supporting the security arrangements. All detainees are accounted for and there is no risk to the wider community."
A second fire, that was unrelated to the first, according to a spokesperson for G4S, was also started by "one of the detainees setting fire to his bedding" on Saturday afternoon. It was extinguished using sprinklers and fire extinguishers.
The spokesperson added that a detainee who assisted in putting out the fire was "slightly injured" and the fire had delayed some detainees being fed.
The then Home Secretary Jacqui Smith opened Brook House, which can house up to 426 people, in March.
It is situated next to Tinsley House, a 136-bed detention centre.