Police are investigating a report of a small explosion outside a house in west Belfast.
The incident happened in the Springfield Road area around 8.45am.
There were no reports of any injuries.
Police later said the incident had been caused by a commercial firework.
Police appealed to anyone who may have witnessed any suspicious activity in the area to contact them on 0845 600 8000 or anonymously through Crimestoppers on 0800 555 111.