SIOUX FALLS, S.D. (KELO) — Sioux Falls Police are looking into a weekend robbery that ended up turning violent Sunday morning.

According to Sioux Falls Police Spokesman Sgt. Aaron Benson, the robbery took place near 10th Street and Cleveland Avenue after 3:30 a.m. Sunday.

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A man had been in the business for several hours, asking customers to buy him a cup of coffee. An employee asked him to leave, but he refused. The man proceeded to walk behind the counter to make himself a cup of coffee when the employee said he needed to leave the counter and leave the business, but the man refused again.

The two ended up on the ground in a struggle when the man got on top of the employee and struck her in the head several times, while pinning her to the ground with his forearm. The employee was able to take a pocket knife from her pants and stabbed the man in his leg and got away before officers showed up on the scene.

The 18-year-old employee had minor injuries and was treated on scene. The man was taken to the hospital with non-life-threatening injuries.

No charges have been filed at this point, but Benson said he expects to see charges in the coming days.