Police have no idea if it was just a sore loser or someone with more sinister motives who left an explosive tennis ball lying in a gutter three blocks from Timpview High School last week.

A Provo resident found three tennis balls lying in the gutter near the high school, according to Capt. Duane Fraser. The person picked the balls up and noticed one felt significantly heavier than the others. The heavy ball also had a silicone patch on one side.The finder contacted police, who cut the ball open and found it was filled with an explosive material. Fraser would not reveal what the contents were.

"It was designed to work on impact," he said. "It had enough explosive filler in there it would have at least burned and been an explosive flash.

The explosion could have injured someone who bounced or smacked the ball with a tennis racket. However, the ball probably was harmless by the time it was found because it had been lying in the gutter for some time and was soaked with rainwater, he said.