Two women tried to lure two girls, both aged 12, into their car in Worksop, police said.
It happened in Eddison Park Avenue at about 1800 BST on Sunday.
The driver of the small, black car is described as Asian and was wearing glasses and the passenger is described as white, in her late teens or early 20s, with long brown hair.
The car had a 2006 registration plate. Appealing for witnesses, Det Sgt Clare Dean urged residents to be vigilant.
She said: "I would like to reassure the local community that we are taking this matter very seriously and are conducting a thorough investigation.
"I would ask residents to remain vigilant and continue to report any activity that seems out of the ordinary."