A former student, who came to watch a football match, was injured.

Minutes before a football match was due to begin at a school near Kolkata, a ball placed on the playground exploded. A former student who had come to watch the tournament was injured.The blast happened inside the campus of the Assembly of God Church school in Dum Dum cantonment around 9am today.According to the police, a black ball was spotted by a local youth while cleaning the playground for a football match. Somebody picked up the ball and threw it to another student who couldn't catch it. The ball struck a wall and exploded, injuring one former student Johnny Haldar, who had come to watch the match."I tried to catch this object that looked like a ball and, perhaps luckily I missed. It hit a brick wall behind me and exploded," said Mr Haldar, who was rushed to the RG Kar Medical College Hospital.Mr Haldar received injuries on his leg and was having trouble with his hearing for a while. Doctors say his condition is stable now.According to the police, crude explosives had been stuffed inside a ball, sealed with tape and probably hurled into the school compound by miscreants.It was a holiday in school and there were no students in the school campus. The football match was to be played by outsiders in the school ground, the match has been cancelled.Investigations are on.The school is one of a chain of Assembly of God Church Schools in West Bengal.