Police officials explained concerned members of the public reported a liquid being thrown over two young men on Castle Street on Friday at approximately 7.42PM.
There is a further appeal for information after the alleged victims fled the scene towards The Old Town before police arrived. They were described as being mixed race and in their late teens. The whereabouts and extent of their injuries are unknown at this stage.
A police spokesman said: “It is unknown when or where the alleged attack occurred, and officers are keen to identify those involved to ensure their welfare and to actively peruse any potential criminal activity.”
“In light of the recent events, it is important to stress that this incident is not being treated as terror-related”.
The incident comes after the recent law declared that people caught twice carrying acid in public should receive mandatory six-month prison sentence.
Assaults involving corrosive substances have more than doubled since 2012 with the vast majority of cases being in London, figures show, however the vast majority of cases never reach trial.
Metropolitan Police figures obtained by the BBC show men are twice as likely to be victims of acid attacks in London than woman after being linked to a number of gang crimes.
Dr Simon Hasting, a criminologist and expert on gangs at Middlesex University said “acid is likely to attract a ‘GBH with intent’ charge while using a knife is more likely to lead to the attacker being charged with attempted murder.”
Home secretary and local MP for Hastings said she intended to ban the sales of corrosive substances to under-18s. Her plan would bring acid in line on the possession of knives in a public place and anyone caught could be imprisoned for up to 4 years.