As well as the Armed Offenders Squad, a team of detectives, police officers and dogs, two ambulances and a Wanganui fire truck were on standby.
Some of the police officers were also wearing special chemical safety suits.
The large cordon in Glasgow St ran from Keith St to Alexander St, with officers diverting traffic around the blocked-off area.
The house at the centre of the sting was an old wooden villa surrounded by trees. People were standing nearby, with some sitting in parked cars along the side streets, with one group parked near the first cordon in Glasgow St where it intersected Alexander St.
The group told the Chronicle they were friends of the occupants of the house and were on their way to see them. A man standing outside the car said the police had the story all wrong and that someone had rung them just to make ``heaps of trouble''.
"They [police] shouldn't believe everything they hear,'' he said.
Two women sitting in the car said a hoax call had been made to police about the occupants of the house.
"You know, like the house was full of guns, and weapons and ammunition and stuff. I mean, fancy believing that anyway,'' one woman said.
"There's always someone wanting to make trouble for you . . . look, there's even police with guns down there. Too much,'' the second woman said.
A local postwoman had been stopped and was sitting on the side of the street next to her bike and post bag.
An elderly woman who lived in the cordoned area was worried because she did not know why there were "police everywhere'' and had called her daughter at work, asking her to find out.
A student sent home sick from Wanganui City College insisted police let him into his house inside the cordon. They allowed him through but told him to go straight home and stay there.
