A siege at a Bullsbrook house is over and a 15-year-old male is in custody, police say.
The nearby Bullsbrook District High School was in lockdown as the drama unfolded this morning.
Tactical Response Group officers are at the scene.
A police spokeswoman said a teenage male was believed to be threatening self harm.
The school was locked down as a matter of safety.
“They’ve just cordoned off the area,” the spokeswoman said. “We do that as a matter of procedure.”
The Education Department confirmed that about 800 students at Bullsbrook, from kindergarten to Year 12, were being kept in classrooms as a precaution.
The incident started about 9.30am.
Police said at about 11am that the teenager had been taken into custody.