A bullet-and-bomb attack on a Trinamul Congress MLA’s car at a petrol pump in Joynagar, South 24-Parganas, minutes after he had got off on Thursday evening left his driver and two local party leaders dead.

“Three people in their early 30s died in the attack on a vehicle that local MLA Biswanath Das had used through the day,” a police officer said.

Das had left the car to visit the nearby party office — deviating from his routine of an evening adda at a tea stall by the petrol pump — around five minutes before the attack. As the car pulled up for a refill at the petrol station around 7.45pm, some 10 to 12 gunmen surrounded it.

Selim Khan aka Babu, the driver, and local party leader Sarifuddin Khan died of their bullet injuries.

Police sources said Amin Sardar, the other Trinamul leader killed, was not inside the car but had hastened towards the petrol pump hearing the gunshots. He died of splinter hits.

“I don’t know the who, why, what or the how of it, but I was most certainly the target,” Das said. “I’m trying to contact party higher-ups. I shall speak at length when I have their clearance.”

While Das’s initial reaction suggested he was not blaming any Opposition party, several of his Trinamul colleagues later fingered the CPM and the SUCI. The Marxists blamed Trinamul infighting.

Joynagar, around 55km from the heart of Calcutta, is no stranger to political violence and had witnessed a fierce turf war between the CPM and the SUCI through the 1980s and the 1990s.

“But an incident like this had never happened before in Joynagar town. This exposes the deep divide in the ruling Trinamul, which has made even ruling party lawmakers unsafe,” said CPM leader Sujan Chakraborty, who is from the district.

Trinamul district president Subhasish Chakraborty dismissed the infighting theory. “CPM and SUCI men were behind the attack. They are doing this in their desperation to regroup.” Rarely on the same page, Saikat Mollah, the district chief of Yuva Trinamul, echoed Chakraborty.

But a senior district administration official said: “The SUCI or the CPM has no presence here.”

The area has over the past few years witnessed multiple clashes within the ruling party, which several senior SUCI, CPM and Congress politicians had joined since the change of guard in 2011. A lot of the infighting owes to differences between Trinamul and its youth wing, a source said.

Intra-Trinamul violence has been seen also in other parts of the state, especially Cooch Behar and Nadia.

District police chief Ajoy Prasad said: “We are getting CCTV footage from the petrol pump…. Investigations, based on eyewitness accounts, have started but it’s too early to comment.”

Local police sources said that Sarifuddin, one of the victims, had several criminal cases against him.