A man brandished a knife in a Hamilton dairy, then fled after hearing the police were on their way.
Officers are appealing for public help in tracking the man.
Acting Detective Sergeant Michael Handley said the man entered the Ellicot Road Dairy at about 1.20pm today and approached the counter. His face was partially covered and he was carrying a black-handled kitchen knife.
"He has struck the blade of the knife on to the counter twice, directly in front of the attending staff member.