Two women and two men were attacked after being verbally abused and followed by a gang of 15 men in Perth.
One victim was left with serious facial injuries that required surgery after the incident on Saturday, March 6, in South Inch Park.
Tayside police said a large group of around 15 males had been congregating near the tunnels underneath the railway in the park.
The gang verbally abused the victims as they walked past before following them and attacking them around 10pm.
One victim was taken to hospital and another also suffered an injury to their face.
Officers said there were two members of the group identified as being responsible.
One is described as white, 6ft 2in tall, with straight black hair and was wearing a light blue Stone Island jumper at the time.
The other is described as white, 6ft, bald with a “noticeably round face” and was wearing a hooded top.
Members of the public with any information that could assist police in their investigation are asked to call 101 or speak to any police officer, using the reference incident 4415 of March 6.
Information can also be given anonymously through CrimeStoppers on 0800 555 111.