Police investigating suspicious activity at a cash machine in Harpenden have released images of three people they would like to speak to for help.

The incidents happened outside Barclays bank on the High Street, between Tuesday, February 17 and Thursday, February 19.

It is believed a device may have been fitted to the cash machine.

Police would like to identify and speak with the people pictured as they may have information which could assist with the investigation.

Anyone who recognises the people pictured or who has any other information, is asked to contact PC Tim Armstrong via the non-emergency number 101, quoting crime reference F2/15/206 or F2/15/208.

Alternatively call Crimestoppers, the independent charity, anonymously on 0800 555 111.