Paramedics have treated 18 people for injuries after a man attacked them with an unknown substance in Selfridges in London.
A man in his 20s has been arrested after two men got into an 'altercation' in the store, with one of them spraying the other with a 'CS gas-like substance'.
Selfridges said some staff members and customers were checked by paramedics for 'irritated noses and throats'.
London Ambulance Service said 18 people were treated at the scene, with two people being taken to hospital for further treatment, Mirror.co.uk reports.
Met Police officers were called to reports of a disturbance at the Oxford Street store at just after 1.30pm today.
A witness, who works near Selfridges, told Mirror Online: "There was quite a lot of police and ambulances.
"They moved to the back of Selfridges, where there's a garage. I heard someone had been pepper sprayed."
Another worker said: "I saw paramedics treating people. They (the paramedics) were trying to clean their eyes."
A Met Police statement from earlier today said: "It was reported that a man, in his 20s, had been detained by security staff after he sprayed another man with an unknown substance, which causes similar effects to CS gas.
"The man was arrested on suspicion of affray. He has been taken into custody.
"A group of nine members of the public have been treated at the scene for effects of the spray.
"Officers attended along with London Ambulance Service (LAS). Enquiries continue."
Photographs from the scene show paramedics treating shoppers after suffering effects from the "gas".
