Kolkata, Sep 12 (IANS): Angry protestors - mostly parents and guardians - laid siege of a West Bengal school Thursday forcing its principal to resign for the death of a minor girl student after being "ragged".

The Mamata Banerjee government derided the "hooliganism" but assured strict action against all those responsible for the girl's death, which her parents claimed was due to trauma and shock following the ragging.

Oindrila Das, 10, a Class 5 student of Christ Church School in Dum Dum on Kolkata's northern outskirts, died Wednesday a week after she was allegedly locked up inside the school toilet by some of her seniors who demanded money from her.

Parents and guardians ransacked the school demanding the arrest and removal of principal Helen Sarkar, alleging negligence and inaction on her part.

With the agitation streching late into the evening warranting heavy police deployment, Sarkar not only apologised publicly for the incident and assured strict action, but later tendered her resignation which was read out by police.

"I take full responsibility and hereby tender my resignation as the school principal," said a police officer read out Sarkar's resignation on the microphone. But the move failed to pacify the protestors as "the resignation was written on a plain paper which has no value".

"Does she think we are fools? We will not deter unless she tenders her resignation formally on the school's official letterhead and sends to the authorities concerned," said a protestor.

Police had a torrid time controlling the protestors and their repeated pleas to calm down failed to have any impact.

The siege was later lifted after Sarkar formally put down her papers.

Meanwhile, Chief Minister Mamata Banerjee called up the bereaved family assuring action.

The National Commission for Protection of Child Rights also took up the matter and asked the state government to initiate a probe.

"The chief minister today called up Oindrila's mother and expressed shock and grief over the girl's death, and assured proper action," the victim's uncle Alokesh Das said.

State Education Minister Bratya Basu later visited the family and promised strict action against the guilty.

"We have already ordered a probe. All those involved in this will be strongly dealt with. But this hooliganism which is going on in the school is completely unacceptable. This should be stopped immediately," said Basu.

School authorities maintained Oindrila did not inform them about being locked up, but her parents rubbished it. A school teacher Kajari Pal said the minor had tried to inform her about the incident.

"She was trying to tell me that something wrong had happened with her, but could not explain properly. So I asked her to bring her parents. But unfortunately she fell ill and eventually died," said Pal.

Yet to come to term with their loss, Oindrila's parents demanded punishment for those involved.

"If those responsible for taking away my girl are punished, we'll be able to live in peace. Moreover, action will ensure such incident do not recur and a precious life is not lost," said Santanu, the girl's father who expressed his happiness over the principal's resignation.

"There were several complaints against her (principal) and I am relieved that she has quit," added Santanu.

The family is also contemplating legal action against a city based private nursing home where Oindrila was admitted before her death, for alleged medical negligence.