The male offender was described as white, tall, of medium build and wearing a black hooded top with the head pulled up. A police spokesman was quoted as saying that the victim was shaken by the attack but otherwise uninjured.
The assault comes amid a spike in hate crime incidents in the UK following a suicide bombing at a concert in Manchester that claimed 22 lives and an attack in London by three terrorists, who drove a van into pedestrians and then went on a stabbing spree, killing eight persons before being shot dead.
Anti-Muslim crimes in the British capital increased five-fold since the London attack, London Mayor Sadiq Khan said last week, warning that police would take a "zero-tolerance approach".
The kind of incidents reported included a bomb threat received by a Muslim school, racist graffiti and a niqab-clad woman being told she should not be wearing the Islamic outfit. Also, a Muslim woman was spat on while a teenaged Muslim girl taunted by a passer-by who said, "when are you going to stop bombing people.