One of the cash machines at Santander in Rams Walk has been boarded up after thieves tried to firebomb it at the weekend.
Police believe the attackers tried to burst open the machine by setting it alight with a flammable liquid early on Sunday morning.
The attack failed and the thieves left empty handed. Scorch marks from the fire are visible on the paving in Rams Walk.
The town was still busy after Saturday’s summer festival and officers want to hear from anybody who saw anything unusual.
If you think you can help, contact Hampshire Constabulary on 101. The crime reference number is 44190301582.