Northumbria Police launched an investigation at Harton Academy, in Lisle Road, South Shields yesterday, after reports that - on Monday evening - an approach was made to the pupils by a female driver in a silver Vauxhall Astra car.
A police spokeswoman confirmed officvers are carrying out inquiries into the incident which involved pupils aged 12 and 13.
A spokeswoman for the school, which has over 1,640 students aged between 11 and 18, said it was making no comment on the matter.
She said: “The school is happy to leave the investigation in the hands of police.”
A spokeswoman for Northumbria Police said the incident came to light after the three pupils had told a teacher how they had been approached by a woman.
The force said it was visiting the school to establish the circumstances around the incident.
A spokeswoman said: “At 5.40pm yesterday evening (Monday) police received a third-hand report three pupils, aged 12 and 13, had told a teacher at Harton Technology College they had been approached by a woman in a silver Astra.
“Officers are visiting the school to speak to the pupils and establish the circumstances around the incident.”
The school, led by head Sir Ken Gibson, also has a sixth form and during its last inspection by Ofsted in January 2013 managed to secure an “outstanding” judgement across all areas.
The Academy also became one of the very first National Teaching Schools in the country and one of only seven in the North East back in 2011.
Anyone with information is asked to contact police on 101 or Crimestoppers anonymously on 0800 555 111.