A woman has been airlifted to hospital after she was stabbed in the chest on a crowded Sydney train when police punched the alleged knifeman

A woman has been rushed to hospital after being stabbed on a crowded train.

The woman, aged 30, was stabbed in the chest while traveling on a train to Armidale from Sydney at 1.30pm on Saturday.

NSW Police responded to reports of a woman being stabbed between Singleton and Muswellbrook.

The train stopped at Ravensworth and emergency services met the woman and her alleged attacker, a 35-year-old man, at the scene.

Police used a stun gun and pepper spray to subdue the man before arresting him.

The woman was airlifted to John Hunter Hospital in serious condition.

The alleged attacker is also in hospital and is currently under police guard.

None of the 167 other passengers on board the flight were injured during the incident.

Even more to come

A woman was airlifted to hospital after being shot in the chest on a train in Sydney at 1.30pm on Saturday (file photo)