His first alleged victim, a 30-year-old woman, told officers that she was walking west along Norton Street in Ashfield at about 8pm on Monday night when she was grabbed from behind as she passed a laneway.

The man is alleged to have put one hand over her mouth and the other around her neck, before the woman managed to push him away and scream for help.

She told police that she last saw him running towards Carlisle Street.

Ten minutes later, a 34-year-old woman was putting her rubbish out in the laneway of Carlisle Street when it is alleged she was struck by a similar attack.

She told police that the man grabbed her from behind, putting one hand over her mouth and the other around her neck, before she screamed for help and he pushed her to the ground.

Described as being about 190 centimetres tall with a thin build and long hair, he was last seen fleeing towards Arthur Street wearing a long-sleeve black shirt with white logos on the sleeves, beige shorts and white sneakers.

"Clearly this is an abhorrent attack on two innocent female victims," Superintendent David Johnson of Burwood Police Area Command said.

"We're really looking for the public's assistance to help us identify the perpetrator so we can put him behind bars where he belongs."

Superintendent Johnson said several items were seized at the scene of the alleged attacks for forensic examination, but the items were confidential due to the nature of the investigation.

He said there was nothing to suggest that the alleged attacks were sexually motivated, and they appeared to be "random".

"People are just to go about their business," Superintendent Johnson said. "This is a very safe area and the police will investigate this like they investigate any matter. We will be conducting our normal patrols as we do usually to keep crime down in the area."

Police are urging anyone with information about the alleged attacks to contact Burwood Police Station or Crime Stoppers on 1800 333 000.