The mother at the centre of a costly siege in Kelmscott says she feared foreign invaders were coming to get her when police surrounded her home.

Rachel Annakin, 33, and her newborn twins were inside their Slee Avenue home when a neighbour reported the sound of gunshot coming from the property on Thursday afternoon.

Parts of Kelmscott, including the local high school, were put into lockdown as heavily armed police moved in.

Camera Icon Rachel Annakin was seen carrying a newborn from the Kelmscott home. Credit: 7NEWS

Ms Annakin said she feared for her babies’ lives when officers carrying machine guns tried to guide her outside her home with lasers.

“In my mind I’m thinking, they might be thinking this is a fake baby or a bomb in my arms or I’ve got a gun under here,” she said.

iPhone footage showed the terrified mother walking out of the house holding one of her babies in her arms.

The mother said she failed to give herself up sooner because she had confused the geared-up, ready to raid tactical response group with foreign invaders.

“I actually thought it was a foreign army doing a terrorist attack,” she said.

Camera Icon Rachel Annakin said she feared heavily armed police were foreign invaders outside her home. Credit: 7NEWS

“When you've got machine guns pointing at you and green lasers and people saying things over a PA and a great big tactical response vehicle and you're getting told to walk at a slow pace and follow a laser with a baby in your arms and my other twin inside, what would anyone think?

“I was in fear of my life.”

The mother said she was sweating uncontrollably during the two hours police had Ms Annakin’s home surrounded.

The 33-year-old was taken into custody on Thursday after the siege but was not charged.

She will be summoned to court to face unrelated drug allegations.

Yesterday, near toys in the family’s backyard, police found a tree stump with bullet holes in it and a homemade pen gun.

Ms Annakin said she knew nothing about the reports of gunfire.

“My house is a safe house,” she said.

“I am so sorry to the parents of Kelmscott High School. No intentions in any way did I try to cause fear to your children.”

Her two babies, who were born premature three days earlier, were taken to hospital by ambulance for unrelated health checks.

Police are still looking for the father of the twins, who had been at the home earlier that day, as they think he could help them with their investigation.