A 17-year-old girl is being treated in hospital after being stabbed in the neck.
Armed officers from Lancashire Police were deployed to the scene in Brierfield, near Nelson, and arrested a 30-year-old man on suspicion of attempted murder.
The force said it had been called to Wood Street at 15:06 BST following reports that a girl had been stabbed in the back of the neck.
It is understood her injuries are not believed to be life-threatening.
A force spokesperson said: “We know that this will cause alarm in the local community and extra patrols will be in the area this evening to provide reassurance.”
Lancashire Police has urged anyone who may have witnessed the stabbing, or who may have CCTV of doorbell camera footage, to come forward.
