Man in clown mask robs Adelaide Subway with fake gun

A man in a clown mask has robbed an Adelaide fast food outlet with an apparent replica gun on Halloween.

Police said the man went into the Hope Valley Subway in the city's northeast at 9pm yesterday with what appeared to be an imitation firearm.

He assaulted an employee and took cash from the till before fleeing into a car park, and is believed to have escaped in a white hatchback.

Police are looking for a man about 170-175cm tall, with a skinny build and a pale complexion, who was wearing a dark hooded top, dark chinos and a clown mask.

Police said no one was injured during the attack.