A knife attack on a nursery worker who was slashed and beaten by three women is being treated as a hate crime, police have said.

The white woman was set upon by three female assailants who reportedly shouted "Allah", according to her colleague.

She was treated in hospital for a minor slash wound and was said to be in shock following the incident on Wanstead High Street in north east London just after 9.30am on Wednesday.

Police said they are appealing for information to trace the three attackers.

"As a result of comments made during the attack, police are treating this as a hate crime," they said in a statement.

The victim, who is aged in her 30s, was set upon as she walked to the nursery where she works.

Karrien Stevens, a colleague of the victim at the Little Diamonds nursery in Wanstead, said the three attackers appeared to be Asian and were "dressed all in black".

The nearby Wanstead Church School was briefly put into lockdown after the attack.

When asked about the incident, London mayor Sadiq Khan said: "It's early days yet but the police are taking it very seriously."

"Various lines of inquiries are being followed and I'm confident that justice will be done."

Anyone with information about the attack can contact police on 0208 345 2711 or reach Crimestoppers anonymously on 0800 555 111.