Police are guarding a shop in Bristol after it was subjected to a suspected chemical attack.

Officers were stood outside the sealed-off Polski Sklep Polish food shop in Gilda Parade, Whitchurch, last night as investigations into the incident on Tuesday evening continue.

The shop was sealed off and three people treated in a decontamination unit after a chemical was thrown in through the door at 5.40pm. Staff reported having breathing difficulties after the attack.

An investigation by Avon Fire and Rescue Service found the substance involved was butanoic acid, which is foul-smelling but non-toxic.

The staff were given showers in a mobile decontamination unit brought to the scene by firefighters, but paramedics found they had suffered no injuries and did not need medical treatment.

Yesterday, police were examining CCTV in the area to try to identify suspects. Police spokesman Simon Whitby said no arrests had been made and witnesses were still being sought.

Anyone with information can call police on 08454 567000 or Crimestoppers on 0800 555111.