Dyfed-Powys Police officers have received information suggesting that a pre-arranged fight, or violence and disorder, is planned to take place between individuals from Welshpool and Aberystwyth "sometime over this bank holiday weekend".
It is believed that the plan is for people involved to meet in Aberystwyth, where there is then "a high potential for disorder".
Inspector Matthew Price said: “The situation is being constantly reviewed, and more information is being gathered.
"Dyfed-Powys Police is pro-actively working to prevent any opportunities for this to take place, and policing plans are being implemented in both Aberystwyth and Welshpool, which will see extra resources patrolling these areas to monitor this closely.
"Our colleagues in British Transport Police are also assisting us in this operation, and will be keeping a close eye on the rail network between both locations this weekend.
“This type of behaviour will not be tolerated, and should anyone get involved in violence or disorder such as this, robust action will be taken against them.”
Anyone who has any information regarding this matter, or sees or hears anything suspicious is urged to contact police either online: bit.ly/DPP101Online, on email: firstname.lastname@example.org or call 101.