Army bomb disposal experts were called to examine the scene of two small blasts in Co Down.
Loud bangs were heard in the Coily Hill Road area of Killyleagh on Sunday night.
The incidents were reported to police yesterdayday.
Detective Sergeant David Cameron said: “Police conducted a search of the area today and found what is believed to be the site of two small blasts. ATO have been tasked to the scene.”
Mr Cameron added: “Police would ask anyone who may have noticed anyone acting suspiciously in the area yesterday evening or anyone who has information to contact detectives at Downpatrick on the non-emergency number 101.
“Or, if someone would prefer to provide information without giving their details, they can contact the independent charity Crimestoppers and speak to them anonymously on 0800 555 111.”