Authorities are passing along warnings to students about the danger of throwing objects onto cars from overpasses.
Authorities are continuing to investigate recent incidents in which rocks were thrown from Kansas Turnpike bridges and overpasses at more than 20 moving vehicles.
"We have some leads we're following up," said Master Trooper Mike Hover of the Kansas Turnpike Authority. "I'd like to tell you we've made an arrest, but we haven't."
Rocks and pieces of concrete were thrown onto vehicles passing under six bridges and overpasses between turnpike mileposts 190 and 195 between Lawrence and Topeka. The incidents occurred between 1 a.m. and 2 a.m. May 7. Six of the incidents were reported in Douglas County.
Damage to the vehicles ranged from minor to broken windshields.
Hover said "definitely more than one person" was involved.
Authorities had planned to hold assemblies with area schools to tell students about the dangers of throwing rocks at moving vehicles.
However, Hover said it's too late in the school year to hold assemblies.
But he has spoken to area high school principals and the KTA has put up informational posters about the incidents at the schools, he said.
Anyone who throws objects from a bridge and causes damage of between $500 and $25,000 to a vehicle can be charged with felony criminal damage. A conviction of the charge carries a maximum penalty of 5 to 17 months in prison and a $100,000 fine.
If someone is injured or killed, charges of aggravated battery or manslaughter also could be assessed.
People with information about the May 7 incidents are asked to call the KTA and ask for Hover or leave their number for him to call them. They may call 843-5826 in Lawrence, 266-5211 in Topeka or 721-2624 in Kansas City, Kan., and dial Ext. 2202 when the automated operator answers at any of the three locations.