Children walking to school in Uttoxeter are on alert after a stranger stopped two young boys and invited them into his car.
He approached the year seven pupils in the town's Asda car park while they were walking to Oldfields Hall Middle School.
He said "I know your mum" and offered them a lift to school at 8.10am yesterday, February 7.
But the youngsters ignored him and immediately told Asda staff what had happened.
Cops describe the suspect as a bald, white man driving a black estate car and wearing a dark, long-sleeved top.
There was no CCTV to capture the offence, but witnesses are being urged to call Staffordshire Police.
Oldfields head teacher Carl Gliddon said: "We're clearly concerned to have heard about this and whenever something of this nature happens, we always take it very seriously.
"But we have systems in place, one of which is to share the information with the police and other schools.
"We also remind our pupils how to conduct themselves when faced with similar situations.
"If youngsters are ever approached by someone they don't know, they should make their way to a public place and inform someone in a position of authority.
"That could mean going to a shop or school, or approaching a police officer.
"They certainly shouldn't be accepting anything from any stranger who approaches them, whether that be a lift or any gifts.
"Many of our youngsters travel to school in friendship groups, which is a good way for them to feel more confident."
A Staffordshire Police spokesman said: "There's nothing to suggest that children are at any risk, but if children are approached in a similar way they are encouraged to use their common sense and not to talk to strangers.
"We would advise they walk away and tell an adult, who they know, straight away or ring the police.
"If you do see anything suspicious report it to us immediately by ringing 101 or, in an emergency, 999."