The incident happened at commercial premises in the Main Street area of Bushmills on Monday, March 4.
Detective Sergeant Rachel Gardiner said: “Shortly after 3am it was reported that two males smashed the window of a bar in the area before pouring some form of flammable liquid inside and setting it alight.
“Damage was caused to an alcove inside the bar as a result of the incident.
“ATO were tasked to the scene this morning as a precaution.
“I am appealing for anyone who was in the area of Main Street during the early hours of this morning and who witnessed the incident or anyone who has any information that can assist with our investigation to contact Detectives on 101 quoting reference 97 04/03/19.
“Alternatively, information can be provided to the independent charity Crimestoppers on 0800 555 111, which is 100% anonymous and gives people the power to speak up and stop crime.”
The Main Street area of Bushmills has now reopened to traffic.