Fireworks were thrown at a property in Helensburgh as an angry crowd of people gathered outside a house in Helensburgh on Monday night.
Officers are appealing for information after disorder in the residential area.
Police Scotland received a report of a crowd gathering at a property at Buchanan Road in the Kirkmichael housing estate at around 7.30pm on Monday, April 28.
Officers attended and the crowd initially were peaceful.
However, a short time later the gathering descended into disorder and fireworks were thrown at a property and some of those present behaved in a reckless manner.
The crowd then moved to the Johnson Court area of the town at around 10.40pm before dispersing a short time later.
One local resident said: “This is terrible. If it happened anywhere else we might find out that this was vigalantes taking the law into their own hands and hunting down people they believed to be paedophiles.”