Northern Territory Police are appealing for witnesses after two separate assaults in Alice Springs on Monday.

Police responded to a report of a woman being assaulted at the self-serve check out of a supermarket on Bath Street around 4:26pm.

It is alleged a man became aggressive and tried to leave without paying. The man was spoken to by the female staff member before he assaulted her with an edged weapon before running from the scene.

The woman was taken to hospital for treatment.

Shortly after, police were called to an incident of assault on a woman in the Gillen area.

It is alleged the woman was riding her bike along the railway tracks when she was attacked by an unknown man, who punched her several times to the head before fleeing.

She was transported to hospital for treatment.

The description of the attacker in both incidents is a clean-shaven man aged in his mid-20s described as having a lead build of Aboriginal in appearance with a lean build.

At the time of the assaults, the man was wearing a grey coloured bucket hat, grey coloured t-shirt, dark coloured long shorts and dirty white tennis shoes.

Officers have released an image of a man they believe may have further details about the assaults.

Police urge anyone who may have information that could assist with their investigation to contact them on 131 444.