Staff at a restaurant were attacked with a glass in what has been described as a “hugely distressing” incident.

Witnesses reported seeing a woman in distress enter Smith and Western in East Street, Horsham, at around 7.48pm on Friday.

Sussex Police said two members of staff were assaulted with a glass – a male employee sustained arm and facial injuries and a female employee sustained facial injuries – and both were taken to hospital for treatment.

The incident was witnessed by an off-duty police officer who had been dining with her family. She detained the woman and called for assistance.

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A 36-year-old woman from Brighton was arrested on suspicion of two counts of causing grievous bodily harm. She remains in custody at this time.

Detective Superintendent Andy Wolstenholme said: “This was a hugely distressing incident witnessed by numerous people, including families with young children, and I’d like to reassure the community that a suspect is in custody as we actively investigate the full circumstances.

“I’d also like to commend the actions of the off-duty officer, who detained the suspect and helped to administer first aid until further units arrived on scene. Officers are never truly off duty in their communities, and in this instance the officer went towards danger without a second thought.”

Anyone with any information about the incident has been asked to report it online or call 101, quoting crime reference 47240224149.