Police have described as a "parent's worst nightmare" the sexual assault of two sisters, aged two and six, in the toilet block of a western Sydney park.
"The parents involved in this are absolutely devastated and so is the immediate family," Detective Acting Superintendent Peter Yeomans told Macquarie Radio on Friday.
"It's horrific, what has happened to them."
The girls were approached by a man inside the toilet block and he indecently and sexually assaulted them, police said.
Police are still looking for the man after he fled the park on Campbell Hill Road in Guildford about 1.30pm on Thursday.
He is described as being of Middle Eastern or Mediterranean appearance, aged between 20 and 30, about 165 centimetres tall, with an average build and facial hair.
He was last seen wearing a black hooded jacket and blue shorts or pants.
Anyone with information should contact Crime Stoppers on 1800 333 000.