Woman assaulted at Sydney brothel

A woman has been assaulted at a brothel in Sydney's inner west in what police believe was an attempted robbery by three young men.

Police say the men entered the brothel at Dulwich Hill at about 1.50am (AEDT) on Sunday and threatened and assaulted the 55-year-old staff member before fleeing.

A police spokeswoman said it's believed the men intended to rob the business.

The first man is described as being 17-20 years old, 170-175 centimetres tall, of slim build, last seen wearing a black hooded jumper with a large yellow symbol on the front over a black baseball cap and gloves.

The second man is described as being 19-20 years old, 175-180cm tall, of medium build and seen wearing a black hooded jumper over a dark baseball cap and gloves.

The third man is described as being 19-20 years old, 175-180cm tall, of slim build and wearing a black hooded jumper and gloves.