Police arrested a 36-year-old man on suspicion of arson, following an alleged incident at the bus and rail station in Bangor this morning.
One bus was completely destroyed and a second one sustained partial damage at the depot on Abbey Street, police say.
Police received the report around 5.10am this morning (Sunday).
The man has been released on bail pending further enquiries.
Sergeant Gibson is appealing to anyone who noticed any suspicious activity in and around the rail and bus depot in Bangor in the early hours of this morning or anyone who has information that could assist police with their enquiries to contact police at Newtownards on the non-emergency number 101.
Alternatively, information can also 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.