An Oxford department store has had to install blue lighting in its restaurant toilets to deter addicts from using them as a place to inject drugs.

Littlewoods' Clarendon Centre branch is one of about 15 of the company's 200 stores nationwide to have fitted the lighting, which makes it difficult for drug users to find their veins.

Spokesman Nicola Rice said it was a preventative measure, put in place in stores that were at risk from abuse.

Signs have also been placed on toilet doors warning customers not to touch discarded needles.

Elderly shoppers and parents with young children told the Oxford Mail they were shocked, but supported the move.

But Thames Valley Police and Oxford City Council said it could push the problem elsewhere.

Iris Goodwin, 66, of Cowley, Oxford, who noticed the lighting while at the store's restaurant with her five-year-old grandaughter Katie said: "I just can't believe it's got to the point where you can't even go for lunch without worrying you might come across drug addicts or needles.

"I'm glad Littlewoods is doing something about it, but it is scary."

Suzanne Holborn, 30, of London Road, Headington, Oxford, who was in Littlewoods shopping with her son Josh, one, said: "I'm very shocked at the thought of people using Littlewoods toilets as a place to shoot up.

"The lighting makes me feel uncomfortable, but if it works, so be it." Lucy Ferguson, spokesman for Oxford police, said: "Putting blue lighting in toilets isn't a preventative measure, it just displaces the problem elsewhere."

Last year, Oxford City Council decided against installing blue lighting in city centre public toilets. It has instead fitted metal boxes to encourage drug users to discard needles safely.

Spokesman David Penney said: "We monitor the boxes and they are proving a success. Blue lighting is not something we support."

Ms Rice said: "The fact that we have taken these steps in a store only highlights that we have recognised the risk and we are confident that we are providing our customers with the safest possible shopping environment."