Commissioner of Police, Barrackpore police commissionerate, Nirad Singh said while cleaning the playground of a missionary school where a match was to be played later in the day, a ball-like object wrapped in plastic was found by a local youth.
The object which turned out to be a low-intensity bomb exploded when he threw it, injuring the leg of 21-year-old Johnny Haldar, Singh said.
Haldar was taken to a hospital and investigation was on, Singh said.
Today being a holiday there was no student in the school premises and the match was scheduled to be played by outsiders in the schoolground.