A member of staff at a shop in Eaton Ford was pushed to the ground and threatened by would-be robbers.
The woman was opening up at the One Stop, in St Neots Street, at about 5.30am yesterday (October 12) when two masked men approached.
They forced their way in, threatened her and demanded money. She screamed, refused to take them to the office and the left empty-handed.
They got into a dark Ford Transit van which was parked outside and drove off.
The men were described as being about 20, wearing dark jackets and fluorescent vests. It is not clear what they had over their faces.
Detective Constable Mark Joslin, who is investigating, said he was very keen to speak to a man on a bike who rode past the shop and was in front of the van as it drove off.
He said: “This was a terrifying incident for the member of staff concerned who was not injured but was upset and shaken.
“I am appealing for the cyclist who rode past to come forward or anyone else that may have been in the area prior to, during or after the incident.”
Anyone with information should call DC Joslin at Huntingdon Police Station on 101 or Crimestoppers, anonymously, on 0800 555111 or via their online reporting system at www.crimestoppers-uk.org