A teenage man has been injured at the Saltfleet Gala event in Louth Road, Saltfleet, on Saturday evening (August 11).
At around 11.45pm, the victim was assaulted with a glass bottle and sustained a head injury which required hospital treatment.
Police are appealing for any witnesses to the attack to come forward.
You can make a report by calling police on 101 and quoting incident number 554 of August 12.
You can also email a report to email@example.com, making sure to include the incident number in the subject box
Alternatively, contact the independent charity Crimestoppers, anonymously, on 0800 555 111 or online at crimestoppers-uk.org.