Kolkata/New Delhi: The Bharatiya Janata Party has blamed the "mafia rule" flourishing under Mamata Banerjee-led Trinamul Congress in West Bengal for the massacre of eight people in Birbhum and demanded Central intervention for restoration of the “collapsed” law and order in a report submitted by its fact-finding team to party president J.P. Nadda in New Delhi on Wednesday.

Chief Minister Mamata Banerjee immediately hit back at the BJP, accusing it of unleashing "political vendetta" against her government and party and of trying to "interfere and weaken" the CBI probe.

The BJP report claimed "state-sponsored extortion, goonda tax, cut-money and tolabazi (organised extortion)” were the main reasons behind the massacre in which eight people were burnt.

Slamming the BJP for trying to "weaken and interfere with the probe" into the Bogtui killings, the West Bengal CM, who was in Darjeeling, said the report mentions the name of TMC Birbhum district president Anubrata Mondal, which “clearly shows the vindictive attitude of the BJP”. She said the report will weaken and interfere with the probe and condemned the BJP's attitude.

She said there should be no interference from any political party in the investigation.

"A government and a party president are not the same. We have extended full cooperation to the investigation underway into the Rampurhat incident. Some BJP leaders visited there and submitted a report to their party president. Such a report amid an investigation will interfere and weaken the probe. It has a political purpose to misuse the probe. It is absolutely a BJP-conspiracy, larger conspiracy now. If it is not, how could they know, without an investigation, who is involved and who is not? The investigation has not been completed even by one-fourth but they have taken a decision and mentioned who is responsible,” Ms Banerjee said.

"When an investigation is on, there should not be any interference from any (political) party or any side. Investigation must be free and fair. Party interference at this moment is misuse and abuse of power which may distort the probe and people will lose their confidence in the investigation,” she said.

Her party colleagues, while promising to cooperate with the CBI which has been asked by the Calcutta high court to probe the incident, had earlier warned of mass agitations if the BJP tries to influence the investigation.

“Under TMC leadership, mafia is ruling in West Bengal in connivance with police and political leadership. Law and order has totally collapsed (due to) state-sponsored extortion, goonda tax, cut-money, tola bazi,” the BJP’s fact-finding team of four retired IPS officers and state unit president Sukanta Majumdar said.

The four retired IPS officers are Rajya Sabha MP and former Uttar Pradesh police chief Brajlal, Lok Sabha MP and former Mumbai police commissioner Satyapal Singh, Rajya Sabha MP and former cop K.C. Ramamurthy, a national spokesperson of the party, and former West Bengal cadre IPS officer Bharati Ghosh.

Eight people were burnt alive in Bogtui village, while one more succumbed to the injuries a week later, after a mob set some houses ablaze allegedly in retaliation for the killing of a ruling TMC leader Bhadu Sheikh on March 21.

The West Bengal government had constituted an SIT to probe the killings that sparked national outrage before the high court decided to hand over the investigation to the CBI.

The fact-finding team alleged it was attacked during its visit and not a single officer or even a constable came to rescue.

The BJP leaders observed, "Local residents have deserted their homes fearing threat to their lives and property. It is recommended that NHRC, NCW and NCWCR visit Bogtui and take confidence-building measures.” They also noted,  "Not even a single officer/constable of West Bengal Police was visible, nobody came to the rescue of the fact-finding team when they were attacked… Our efforts to contact the DGP and other officers failed.”

After submitting the report to Mr Nadda, West Bengal BJP president Sukant Majumdar, briefing the media said the state urgently needs central intervention for restoration of law and order as “complete lawlessness” prevails and the state police is colluding with the ruling TMC.

Outraged by the explosive charges, Ms Banerjee said, "I condemn the attitude of the BJP and the Central government… Party interference at this moment is absolutely misuse and abuse of power. The misuse of power will mislead and distort the investigation. People will lose confidence in the investigation. I will request them (BJP) to behave properly."

The TMC supremo argued, "I have seen they mentioned our district president's name in the report. This is a very bad, rough, negative, biased and vindictive attitude. How could they mention his name without investigation? It means they want to arrest him. That is a personal vendetta. They want to arrest all the political party fellows and their family members and party members, whoever is opposing them, throughout the country. They are trying to evict all the parties forcefully with a political vendetta."