LONDON, United Kingdom (AFP) – Buckingham Palace is to investigate after a household staff member was arrested at a London bar following a Christmas party brawl, a palace spokesperson said on Friday.

A 24-year-old woman was arrested at the bar a short walk from the royal residence after smashing glasses and attempting to assault a bar worker on Tuesday night, according to London police.

The event was an “informal social gathering, not an official palace Christmas party”, a Buckingham Palace spokesperson said.

“We are aware of an incident outside the workplace involving a number of household staff who had previously attended an early evening reception at the palace,” the spokesperson said.

The brawl took place at an event involving around 50 palace staff, according to The Sun tabloid newspaper.

The woman was arrested on suspicion of common assault, criminal damage, and being drunk and disorderly.

“The facts will be fully investigated”, the palace said, adding that “robust disciplinary process” would be followed for the staff concerned.