Two men allegedly tried to rob the attendant of a Ramsgate Road, Broadstairs garage about 6.20pm on Monday night.
One man walked around the back of the counter, pulled out a black handled kitchen knife and told the attendant that he was being robbed, while the second man stood in front of the counter.
The attendant confronted the man with the knife and told him not to be stupid as he was self-defence trained.
The two men, who were both wearing black scarves over their faces, then left the store empty handed.
The man with the knife was white, aged between 16 and 19, about 5ft 10in tall, of medium build, and wore a dark grey ‘hoody with white stripes down the sleeves and dark jeans.
The other man was white, aged between 16 and 18, about 5ft 8in tall and wore a white hoody.
Anyone who witnessed the incident or has any information is asked to contact DC Katrina Whitehead at Margate Police Station on (01843) 222 151. (ref 394)
Unless a contact number is given, anyone with information about an incident should contact the police on (01843) 222 033 or Crimestoppers on 0800 555 111.