Shoppers howled in horror and children were left crying after a man claiming to have hepatitis C spread blood from a wound on his arm around a B&M store.
The 47-year-old threatened staff, dripped blood around the aisles and blocked the exit of the shop leaving customers terrified.
Staff originally suspected the man had been shoplifting before he his bizarre outburst.
Connor Lee was shopping with his partner at 3.30pm on Monday afternoon when he heard people screaming.
Connor, from Dewsbury in Yorkshire where it happened, told Examiner Live: "He decided to block the exit door by putting his blood all over everything. He was standing in the middle of the doors with his hands toward the tills but as he was covered in blood I don’t think anyone wanted to go near.
"He was escorted out [by staff] more than twice but refused to stay out of the store.
"He stared spitting it in the store and he was opening his wounds further as if to make them bleed more.
"He seemed like he was out of it - not all there. I don’t think he knew what he was doing if I am being honest."
The man had originally been confronted by staff who suspected him of shoplifting.
Connor said when the police arrived they managed to subdue him so he could receive medical attention.
He explained: "The police and armed response held him away from the shop until the paramedics applied first aid.
"Then I believe they escorted the ambulance to the hospital."
The ambulance services confirmed the man was taken to a nearby hospital with a hand injury.
A spokesperson for the police said: "A 47-year-old man has been arrested following an incident at a shop on Wilton Street, Dewsbury, yesterday afternoon (Monday July 8).
"Police were called shortly before 3.40pm to reports that a man had assaulted staff after being confronted on suspicion of shoplifting.
"The man had laceration injuries and was taken to hospital for treatment. He has since been released and taken into custody."
