Detectives are looking for six men after a fight broke out at a Cardiff Bay restaurant.
Emergency services were called to Las Iguanas in Mermaid Quay at around 8.20pm on Wednesday evening, where four men had been sitting.
Two other men ran into the restaurant on Tacoma Square and threw a liquid at them, alleged to have been a corrosive substance.
Furniture was also picked up and thrown before both groups ran out of the restaurant.
No one was injured, and according to police, the substance involved in the incident was not harmful.
A cordon was put in place with the public urged to avoid the area, but it was lifted by 11pm.
But it's understood the six men had also been involved in another altercation in another part of Mermaid Quay at around 6.15pm.
South Wales Police are treating the incident at the restaurant as a targeted attack - and they are appealing for witnesses or anyone who was in Mermaid Quay at the time of the incident to come forward.
Detective Inspector Phil Marchant said: "We acknowledge the considerable public concern following this incident however no injuries have been reported and at this time the liquid is not believed to have been harmful."
He added: “Inquiries are ongoing to identify and locate all six men.”
"Officers would like to speak with anyone who was in Las Iguanas, or the vicinity of Tacoma Square, between 6.15pm and 8.30pm who may have information that could assist their inquiries."
Anyone with information should contact South Wales Police on 101 or use the live web chat, quoting reference no. 2400378983.
Alternatively, contact Crimestoppers anonymously on 0800 555 111.

Former Holm View Leisure Centre could become education and community hub
ScoutsCymru members represent Wales at Royal Albert Hall Festival of Remembrance
Plans for indoor market at former Barry Wilko move forward
Police given additional powers to deal with anti-social behaviour in Barry
Senedd passes supplementary budget with £60m boost for additional learning needs
Future of planned festive events in question after criminal damage to Barry Town Hall
Consultation to open on plans for 35MW solar farm near Penarth
No Trains through the Vale of Glamorgan this Sunday
Police and Cardiff City launch operation to tackle matchday anti-social behaviour
Free leaf and fallen fruit collections return in the Vale
Barry retains Fairtrade Town status until 2029
£1m improvements planned for Pencoedtre Park as splashpad work set to begin
Plan submitted for new independent school on site of well-known charity farm
Is your hot water bottle safe?
Solicitor sentenced for defrauding Cancer Research UK
Cate is crowned champion!
WATCH: Winner of The Voice UK Cate McHugh duets with Sir Tom Jones
Barry filmmaker takes her documentary to the big screen in New York
Pupils leave their mark on new school at steel signing event
£3m refurbishment plans revealed for Cowbridge Town Hall