Satyajit Biswas was rushed to the nearby Shaktinagar district hospital, where he was declared dead. (File photo)

Trinamool Congress (TMC) MLA Satyajit Biswas was shot dead by unidentified assailants inside a Saraswati puja marquee on Saturday evening in West Bengal's Nadia district.

Biswas, an MLA from Krishnaganj constituency, was killed in full public view. A number of senior TMC leaders were present at the event when the attack took place.

The ruling TMC alleged it was a planned attack by the BJP, while the saffron party claimed it was the result of the ruling party's infighting.

The TMC leader was shot from point blank range when he was coming down from the dais, police said. The MLA was immediately taken to the nearby Shaktinagar district hospital where doctors announced him "brought dead".

A high-level inquiry has been ordered into the killing. A firearm, a desi pistol, suspected to have been used in the crime was found in a nearby area.

TMC Secretary General Partha Chatterjee said the party was shocked at the killing of the "popular youth leader".

"Words fail me. Recently BJP leaders tried to stoke tension in the area. This was an orchestrated plan to eliminate him, designed to try and benefit BJP. People will give a befitting reply to perpetrators of this dastardly act. Those who have killed him will not be spared. Those responsible for his death will be brought to book. BJP is responsible for this shocking death," he said.

"It was a pre-planned murder by the BJP. They have hired goons to carry out the murder," the party's in-charge of Nadia district Anubrata Mondal alleged.

BJP state president Dilip Ghosh denied the charges and claimed that the killing might be the result of infighting in the TMC.

"The allegations are baseless. The BJP is not at all involved in the case. Those who are blaming us are actually trying to hide their own sins," Ghosh said.

Senior BJP leader Mukul Roy also termed the allegations as baseless.

Reacting to the killing, state Congress president Somen Mitra said it showed that "complete lawlessness and chaos" prevailed in the state.

"The chief minister claims that law and order is good in West Bengal, but this incident shows the true condition...It's complete lawlessness and chaos that are prevailing in Bengal. We demand the CM give an explanation on how could a sitting MLA be murdered," Mitra, who is in Delhi for a party meeting, said.

(With inputs from PTI)