UPDATED: North Yorkshire Police now say the man was seen acting suspiciously to the rear of a building at the site, but they do not now believe it was an attempted robbery.
However, they still want to speak to anyone with information about the incident.
POLICE are investigating an attempted burglary on the Dunnington Industrial Estate this evening.
Officers in at least two police vans have been sent to the area after reports of the incident at about 6.15pm.
A North Yorkshire Police spokesman said a male suspect was seen running from the scene, and was described as white, aged in his 20s, about five feet nine inches tall, with a skinny build and wearing a grey hoodie.
He said the man was believed to have discarded a hammer used in the attempted burglary as he fled the scene.
Anyone with information which could assist police should phone 101.