The centre has issued an advisory to Mamata Banerjee's government over "unabated violence" in Bengal.

The centre has expressed deep concern over the continuing violence in Bengal even after the national elections and issued an advisory to Mamata Banerjee's government, sources said. The state BJP had approached home minister Amit Shah, claiming three of its workers were killed by Trinamool Congress workers in the North 24 Parganas. This was the third instance of violence in the last 10 days, in which one Trinamool worker was also killed.

"The unabated violence over the past weeks appears to be a failure on the part of the law enforcement machinery of the state to maintain the rule of law and inspire confidence among people," read the home ministry's advisory to the state.

"It is strongly advised to ensure that all necessary measures are taken to maintain law and order, peace and public tranquility. It is also requested to take strict action against officials found delinquent in discharge of their duty," the advisory read. Mr Shah has also sought a report from the state government in this matter.

"Union Home Minister has asked for a report from the state government and I am sure centre will take this up seriously. There is a lot of anger among the people over the incident," Kailash Vijayvargiya, BJP National General Secretary, was quoted as saying by news agency ANI.

The Trinamool called it a conspiracy against the Mamata Banerjee government. "Why are they sending advisories to Bengal, a peaceful state? Why no advisory to UP and Gujarat? It's a conspiracy against Mamata Banerjee, Bengal and the government. We dare them impose Article 356 (President's Rule)," party leader Partha Chatterjee said.

The workers of the Trinamool Congress and the BJP have been on a spiral of violence as the turf war in Bengal gains momentum. In the recently-held Lok Sabha election, the BJP increased its tally from two to 18 of the state's 42 seats. Mamata Banerjee's party was slightly ahead with only 22 seats.

With the next prize being the assembly elections two years away, the Trinamool is determined not to cede any space. Ms Banerjee had skipped Prime Minister Narendra Modi's oath after the BJP said they would ferry the families of 52 murdered party workers to Delhi for the ceremony.

Over the last week, at least three clashes were reported from the state, in which three men were allegedly killed -- two from the Trinamool Congress and one from the BJP.

Yesterday's clashes took place in the evening at Nayjat, about 70 km from Kolkata. Workers from the two parties had come to blows over the removal of party flags from public places. A Trinamool worker was show and then hacked to death. Two BJP workers were killed - one of them shot through the eye.

As a huge police force was rushed to the area to maintain calm, another person was killed in what locals said was a factional fight within the Trinamool in Hooghly district.