Patrols have been stepped up in the Silverstone area of Northamptonshire after four young girls reported being approached by two strangers in a van.
The drivers of the black van first approached two girls in the village just before 5pm on Tuesday, July 14.
They asked for directions, but the young girls refused to talk to the men and ran away.
Two more girls were then approached by the van drivers, but again, the girls ran away without speaking to them.
Both of the men were black and the driver was bald but had a beard. He was in his 30s.
Witnesses, or anyone who knows anything about these incidents, can call Northamptonshire Police on 101, or Crimestoppers anonymously on 0800 555 111.