A 15-year-old girl who had represented Bengal in a national volleyball championship was stabbed to death by a youth after being chased around 100 feet at Barasat, in North 24-Parganas, on Friday afternoon.

Sanghita Aich, a Class IX student at Barasat Girls' School, had been practising for a tournament along with some teammates and their coach when Subrata Sinha, 20, assaulted her. Witnesses said the accused, also a volleyball player, stabbed her at least twice in the head and neck after a chase.

A neighbour of the slain teenager said she and Subrata had known each other for around a year.

The incident occurred around 4.30pm, when Sanghita had been practising on a ground belonging to the Notunpukur Association, a club based in Barasat, about 25km from the heart of Calcutta. She had been a member of the club for around three years and had represented it in various volleyball tournaments.

Coach Swapan Das was busy putting the players through their paces on Friday when Subrata entered the ground almost unnoticed and lunged at Sanghita, police quoted witnesses as saying. "When Subrata entered the ground, he didn't have a weapon in his hands. But while approaching Sanghita, he took out a sharp weapon that looked like a dagger," the coach recounted to Metro.

Subrata allegedly threatened to kill Sanghita on nearing her, prompting her coach to rush to her defence. "Sanghita was scared and she hid behind me. I picked up a plastic chair to stop him from attacking the girl," Das said.

The youth allegedly threatened the coach, too. " Tui jodi samne aashis, tokeo mere phelbo (If you try to interfere, I will kill you as well)," he was quoted as saying.

For about five minutes, Subrata held the sharp weapon in his hand and allegedly continued to abuse and threaten Sanghita. The teenager panicked and started running.

"Subrata chased and caught up with her around 100 feet from where we had been standing. He stabbed her with the weapon at least twice," Das said.

The other witnesses, including teammates of the victim, were too shocked to react. "Nobody dared go near Subrata because he was still brandishing the weapon," the coach said.

As Sanghita lay on the ground bleeding, Subrata fled, taking with him the weapon used to attack her. Sumit Das, a youth from the locality who was on the ground, gave chase but Subrata had disappeared into a lane by then.

Sanghita was taken to Barasat District Hospital, around 2km from the ground, on a cycle van. Doctors at the hospital pronounced her dead on arrival. The post-mortem was done in the evening.

Officials of the West Bengal Volleyball Association said Sanghita was part of the state team that played in the under-14 national championship in 2013. "She had been practising for a tournament scheduled to be held at the Notunpukur ground on Saturday and Sunday," said Paltu Roychowdhury, general secretary of the association.

The police said Subrata was a resident of Shyamnagar, a North 24-Parganas neighbourhood more than 40km from Barasat. He plays volleyball for a local club there.

Investigators said the motive for the murder could not be immediately ascertained.

Sanghita lived with her parents and brother at Notunpukur, close to the ground where she was killed. Her father Tapas Aich is a clerk at Barasat Municipality. Mother Prabha is a homemaker.

"Subrata would frequently disturb my daughter. I had complained to the police about this earlier, but didn't lodge a formal complaint," the victim's father said.