A 15-year-old boy has been arrested on suspicion of attempted murder after a teacher was attacked, police have said.
The assault happened at a school in Milford Haven, Pembrokeshire, Dyfed-Powys Police said.
Officers said they responded to a report on Thursday afternoon that a teacher had been assaulted by a pupil.
They said the teacher was injured, but it was not a stab injury.
Superintendent Chris Neve said: "We can confirm police are at Milford Haven Comprehensive School following a report of the assault of a teacher by a pupil brandishing a weapon at the school at approx 3.20pm.
"The teacher's injury is not a stab injury. A lockdown was implemented but has now been lifted.
"The teacher is receiving medical treatment for their injuries."
Supt Neve added that "all pupils at the location are safe and most have gone home".
Officers remain at the school.
Supt Neve also said: "A 15-year-old boy has been arrested on suspicion of attempted murder and is in police custody."
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