CCTV images have been released after a woman was throttled on the platform of a train station.
A police spokesman said the suspect and another woman were having a "heated argument" at Weston-super-Mare station.
The aggressor grabbed the victim around the neck and started throttling her, he said.
Two station staff managed to pull her off but she verbally abused and tried to attack them. Officers would like to speak to the woman pictured.
The incident happened at about 1200 BST on 15 September.
British Transport Police would like to identify and speak to the woman pictured in connection with the assault.
Investigating officer Pc Lauren Humphreys said the staff had handled the situation "brilliantly".
She added: "Their intervention allowed the victim to escape any injury, as she was able to board a train and flee from her attacker."
The suspect is believed to have left the station and headed towards the town centre.
The force is appealing for anyone with information to contact them.