The 17-year-old boy, who is in Class XI of Summer Villa School in New Ashok Nagar, is in a critical condition and underwent a surgery on his head in Dharamshila Cancer Centre where he was rushed to.

He jumped from the building after he was caught by his teacher with a bottle of alcohol in his bag and was taken to the Principal, a senior police official said. The Principal then telephoned his parents when the boy reportedly panicked and ran out of the room and allegedly jumped from the third floor of the school building, the official said.

"Two schoolmates tried to stop him but he managed to free himself and jumped," the official said adding he suffered critical head injuries. "We don't know how he fell. We will know only after he recovers," said the victim's mother. His parents said they do not have any complaints against the school as it did not appear that there were any lapses on its part so far.

The student is learnt to have been warned thrice earlier and the last one was for bursting crackers in school campus, the official said. He said police would examine the footages from CCTVs installed in the school campus to get possible clues about the incident.

"It appears that it was his panic which led to the incident. We are investigating the matter," the official said. Raja Ram Dutta, Medical Superintendent of Dharamshila Cancer Centre, said neuro-surgeons conducted the boy's surgery.