A masked man armed with a machete threatened workers at a convenience store in Kettering before walking out with a tills-worth of money this morning.
Police were called to Co-operative Food in Stamford Road to reports of an armed robbery at 7.15am.
Staff told officers that a man with a blue scarf around his face walked into the shop and took the unknown amount of cash before walking out of the shop and turning left.
A police spokesman said officers were out on the streets looking for the suspect.
He is described as 5ft 10 inches tall and was wearing a black coat, light grey track suit bottoms and black trainers.
He was carring a sports bag.
Anyone with information should call police on 101.