The Class XI student, Rahul Singh, has been seriously injured. He had sustained wounds on his shoulders and stomach and is at present admitted in the Deen Dayal Upadhyay Hospital.

Doctors have said he is now out of danger.

Lying on the hospital bed, Rahul said: “I was trying to break up a fight when things started getting out of hand. I didn’t see the knife coming. This boy slashed at my shoulders, then jabbed the knife into my stomach.”

Witnesses to the incident said, the offender, a student of Class VIII, and another boy, had passed nasty comments about Rahul’s sister when they saw the siblings talking to each other near the school’s volleyball ground.

His sister studies in Class VII in the same school.

After the boys muttered the words, Rahul objected and even hit one of them. Following this, the two boys, their strength shored up by a senior, Deepanshu, began raining blows on Rahul.

Rahul’s friends rushed to his defence by which time the boy realised the brawl was becoming serious.

He was trying to calm things down when the knife came out.

Police officers said it was a very sharp knife. Student Prateek Kumar said, “This boy snatched the knife and stabbed at Rahul.”

Rahul’s father, lawyer K K Singh, said he was first informed about the incident by the school’s teacher Mithlesh Pandey.

“He is out of danger now but is under observation,” Singh said.

The police have registered a case under Sections 324, 323 and 341 against the boy. The knife used was actually a serrated cutter, the kind students carry to class, they said. An officer said, “We are verifying the facts. The boy will be arrested if need be.”

Rahul stays with his parents at WJ 294, Saad Nagar in Dabri.

He had joined Kendriya Vidyalaya in Class VIII, prior to which he had studied in Bihar.