• A diabolical Facebook post uploaded from a corner of North 24-Parganas snowballs into communal strife that spreads to Basirhat town on Thursday. The BJP has already demanded President's rule in Bengal.

• The demand for Gorkhaland acquires fresh life and an indefinite strike is called. The BJP claims breakdown of law and order in Bengal.

• The CBI and the Enforcement Directorate display remarkable alacrity in pursuing the Narada payoffs case and summon Trinamul leaders. The BJP predicts the end of Trinamul rule in Bengal.

In politics, nothing happens by accident. If it happens, you can bet it was planned that way.

Whether Franklin D. Roosevelt said this or not is a matter of dispute but a section of the Bengal government thinks the confluence of the three events is more than mere happenstance.

"There is a master plan and the three-pronged attack is part of that," said a source in the government.

The manner in which the three events are playing out in Bengal has fed the state government's suspicion that the ruling party at the Centre wants the unrest to continue.

"A Facebook post triggered the problems in Baduria in North 24-Parganas. After some efforts, we could restore peace in the area.... But today, the problem spread to Basirhat town (15km away) and nine Trinamul party offices were burnt. BJP leaders are planning to visit the area tomorrow. Why? To create more tension?" asked a source close to chief minister Mamata Banerjee.

The chief minister today appealed to all political parties to steer clear of the troubled spots till normality returned.

But led by Roopa Ganguly, a BJP team vowed to tour the area tomorrow "to stand by the victims" of the "communal clashes". A central team is also planning a visit.

Several BJP leaders said in private that the situation in Bengal had never been "this favourable" and the party was keen to use it to realise the " Ebar Bangla (This time, its Bengal)" target set by party president Amit Shah.

"Communal tension in the plains, the strike in the hills.... Senior Trinamul leaders are bogged down in corruption cases. We have a great opportunity," said a BJP leader.

Trinamul leaders are convinced the "opportunity" whetting the appetite of the BJP leaders is a "manufactured one".

"The sudden interest of the central agencies in the Narada case is a giveaway.... The BJP is trying to weaken us while the government is saddled with other problems," said a source, referring to the summons the CBI and the ED have sent to Calcutta mayor Sovan Chatterjee and other Trinamul politicians.

In off-the-record conversations, BJP leaders had said in the past few days that the arrest of a few Trinamul leaders in corruption cases was just a matter of time.

There is little doubt that the Facebook post in North 24-Parganas has pitted one community against the other in Baduria. But, several senior officials in the police and civil administration told this reporter, the trouble that followed in places like Basirhat town was the handiwork of "rogues and known criminals".

"Basirhat is a peace-loving town. People from all communities in Basirhat have told us they want the trouble to end, but some criminals will not let peace prevail," a police officer said.

Local Trinamul leaders, along with elected representatives from the Congress and the Left, have started peace initiatives in the affected areas. Opposition leaders in Bengal - barring those from the BJP - have underscored the need for an immediate return to normality.

But BJP leaders - from party general secretary Kailash Vijayvargiya to state president Dilip Ghosh - have described one community as the victim and accused the Mamata government of appeasing another.

"BJP ministers and senior functionaries are openly spreading provocative messages on Facebook and Twitter. This is a crime.... When you cannot defeat Trinamool on social, economic or development indices, what does BJP do? Go back to a tried and tested dirty trick: polarisation," Trinamul leader Derek O'Brien said in a statement.

Going public with what senior government officials have been saying in hushed tones since the unrest in Darjeeling began, O'Brien added: "BJP dirty tricks department also active in Darjeeling."

A section of officials has been saying that the Gorkha Janmukti Morcha, an ally of the BJP, enjoys the tacit support of the Centre.

"The BJP may be supporting the Morcha because of political compulsions, but is it prudent, given Darjeeling's geographical position?" asked a government source, referring to the borders the state shares with Nepal and Bhutan.

With China courting the two Himalayan neighbours - and also Bangladesh - the state government feels the BJP is playing with national security.

"China today threatened to support 'pro-independence appeals' in Sikkim.... There are reports of Chinese influence in the Darjeeling hills. Isn't the BJP playing with fire?" asked a government source.