Schools have warned parents and pupils to be vigilant after a van driver grabbed a 12-year-old girl and tried to get her and a friend into his vehicle.
The two girls were approached by a man driving a white van in Harrington Street, Bourne, at about 8.30am on Tuesday.
The driver tried to talk the girls into getting into his van before grabbing one of them by her clothes.
The girls, who are both 12, ran away and joined another group of pupils making their way to school.
The secondary schools in Bourne are both aware of the incident. Bourne Academy has written to parents.
A letter from Bourne Academy headteacher Laurence Reilly said: “We are aware that police are investigating the situation and over the next few days and weeks I am asking all students and parents to be vigilant in reporting any such incidents or situations of suspicious behaviour immediately to the police by calling 101 and quoting incident 241 of March 5.
“All students have been informed of the situation through special assemblies held today.”
The driver was described as white, in his 30s with brown hair over his ears. He was wearing sunglasses. The passenger was black.
Police have stepped up patrols in the area around school start and finish times as a result of the incident.
Community beat sergeant Rachel Blackwell said: “Anybody approached in this way is advised not to engage with the person.
“Get to a larger group, speak with an adult or go into a shop.”
The van driver was white, middle-aged with brown hair. Police believe the van may have been a Ford Transit.
A similar incident was reported in Bourne earlier this year. On January 29 two men in a white van pulled up beside a 10-year-old boy walking to school in Nowells Lane.
One is reported to have said: “Get in and I’ll give you some sweets.”