A armed man has barricaded himself inside a house in Sunbury, following an alleged dispute.
Officers were called to reports of a dispute at Magdalene Court just before 11am.
Subsequently a man armed with a firearm has barricaded himself inside a property on Xavier Court.
Police have cordoned off the area and are currently attempting to negotiate with the man.
Members of the public are advised to avoid the area and if they are nearby, to stay indoors until the incident is resolved.