Four men aged between 34 and 52 were injured and taken to hospital after the lunchtime attack near Covent Garden, the ambulance service told Sky News. Two of them have been able to leave hospital, and the other two are not believed to have life-threatening injuries.
A woman has been arrested on suspicion of the attack, police say. She is believed to be suffering from mental illness, and the attack is not considered terror-related.
Covent Garden in central London is a popular tourist destination.
