An eye-witness, who wished to remain anonymous, said: "a customer stabbed himself...they closed the store as police and ambulance were there and there was blood everywhere...not a nice sight to see up there..it was shocking for staff to see."
West Yorkshire Police have confirmed they were called to the store, in Killingbeck Drive, at about 6am this morning (Wednesday).
A male was found with injuries.
He has been taken to the hospital.
His injuries are serious but not believed to be life-threatening.
Officers are satisfied this has been a self-harm incident with no other person involved and there are no suspicious circumstances.
At about 9am police released the scene to allow normal business to resume at the store.
The Samaritans offers emotional support for anyone struggling with mental health issues or suicidal thoughts 24 hours a day, seven days a week.
For support, please contact Samaritans helpline on 116 123. This number is free to call.