ELKHART, Ind. (AP) _ Police and school officials in northern Indiana are boosting security at local schools following an anonymous threat warning that 20 schoolchildren would be killed on April 15.
 
  The Elkhart Truth reports Lt. Matthew Blank of the St. Joseph County Police Department said Tuesday the threat against five schools in Elkhart and St. Joseph counties was discovered in mid-January in Elkhart County.
 
  Blank declined to detail how the threat was made, but compared it to a scribble on a bathroom stall.
 
  Doug Hasler of Elkhart Community Schools executive says the threat “has our attention.” He says the district is working with police to make sure “our schools are as safe as possible.”
 
  Elkhart County Sheriff Brad Rogers said Tuesday the department will increase its presence at area schools.