A sleepy neighbourhood at Behala Manton was shaken out of its slumber on Wednesday night by a bomb hurled at the house of yet another "CPM family" targeted for reprisal after a ballot that blunted poll thuggery.

Former MLA Kumkum Chakraborty, 66, and husband Tapan, 70, had just returned from a Chinese dine-out when the bomb exploded on their two-storey house in Jayasree Park around 11.15pm.

"There was an explosion and we heard glass being shattered on the ground floor. I ran towards the balcony but did not see anyone. I ran downstairs and found the entire living room strewn with shards of glass. The smell of gunpowder hung in the air," Chakraborty, who was the MLA from Behala West constituency from 2006 to 2011, told Metro.

Chakraborty's husband used to be a full-time CPM member while the couple's daughter Shamayita was an SFI leader in her college days.

The impact of the explosion shattered the aluminium frame and glass pane of a ground-floor window. Shards of glass were all over the sofa, centre table and the kitchen at least 20 metres away. A crude bomb that didn't explode was found near the main door.

Chakraborty had campaigned for Jadavpur University professor and Independent candidate Ambikesh Mahapatra, who is contesting the Behala East seat against the sitting MLA and mayor Sovan Chatterjee.

The former legislator told police that she suspected Trinamul Congress supporters to be behind the attack on her house, located barely 2km from Senhati Colony where gunmen had opened fire on the house of CPM member Arindam Jha early on Wednesday.

Jha had been in charge of the party's poll campaign in a part of Behala. He was also a party candidate in the civic polls last year.

"It looks like Trinamul Congress supporters have become frustrated after failing to loot votes this election. They know their party is going to lose and so they are resorting to such shameless attacks," Chakraborty said.

Chakraborty said the bomb attack on her house had left her family shaken but not afraid to stand up to those responsible for it. "My daughter hadn't returned home when the explosion occurred. I called her and she said she was in a taxi with my brother-in-law. I informed her about the attack and asked her to stay alert," she recounted.

Shamayita, who works in Bangalore, said her family had never been the target of violence before Wednesday night. "Our entire family has been with the CPM for years. But never before did we face an attack like this. Not that we are afraid."

Her words echoed those of Jha's mother after the firing incident the previous night. "I am not afraid. Members of our family have been committed CPM supporters for years," Chandra Jha, 62, had said.

Trinamul workers had assaulted the nine-year-old granddaughter of a CPM supporter in Haridevpur, under Behala East constituency, on the night of April 30. They were looking for Amulya Bor, 70, because he had voted in the election in defiance of their diktat.

Mayor Chatterjee visited Amulya's granddaughter Priti on Monday and rebuked his party supporters in front of television cameras. " Ei tora keno orokom korechis (Why did you do this)?" he said, admitting Trinamul's hand in the assault.

On Thursday, Chatterjee said he suspected CPM members had hurled the bomb at Chakraborty's house to "grab media attention and create political tension".

"Why would our men attack prominent CPM leaders twice in a single day? If a leader of Chakraborty's stature is attacked, it is evident that our party would be dragged into it. Why would our party do such a foolish thing? I think CPM men are behind the attacks," he alleged.

The mayor said he had called the Calcutta police commissioner along with the deputy commissioner of the south-west division to press for an investigation. He also deputed local councillor Manik Lal Chatterjee to visit the Chakraborty family.

The councillor told the Chakrabortys that he was "astonished" by the attack. As he stepped out, Manik Lal Chatterjee told reporters that he suspected the attack was masterminded by the CPM. "You need to understand which party will benefit from the attack. Not Trinamul Congress. Then it is obvious which party could have done it," he said.

More than a dozen cops and an entire bus of Heavy Radio Flying Squad personnel were stationed outside the Chakraborty residence since early on Thursday.

"Nobody has been arrested yet, but we have some leads and are working on them," said Meeraz Khalid, the deputy commissioner of police (south-west division).