EMINENCE, Ind. (AP) _ High school officials say a senior prank became a health hazard when someone spread hundreds of pounds of manure on school doors and around the building and put dead animals, animal blood and stolen ``for sale'' signs outside the school.

``2004'' was painted on the grass, leading officials to believe Eminence High School seniors are responsible.

``I call it vandalism,'' school Superintendent Norman Stockton said Tuesday after working three hours on the cleanup. ``We have had incidents in the past, but I see this as vandalism.''

It took several trips with a front-end loader to remove the manure from the school about 30 miles southwest of Indianapolis.

Classes were delayed an hour, and the kindergarten graduation in the high school gym was pushed back 45 minutes. Principal Max Hoke canceled a senior class trip to the Indianapolis Zoo.

Stockton said school officials would prosecute if the guilty parties were found, and the Morgan County Sheriff's Department was investigating.

Officials believe they can narrow down the field of suspects with 40 members in the senior class.

``It probably wasn't the whole class. I figure there were a half-dozen kids or more involved,'' Stockton said.

Senior class president Kyle Malott, 18, said he would have preferred having those responsible for the prank clean up the mess, rather than canceling the trip to the zoo.

``I will say it wasn't smart,'' Malott said of the prank. ``Something that affects (the operation of) the school is pretty extreme. It was uncalled for.''