At least four persons were killed in poll-related violence on Thursday, two days before voting for the three-tier panchayat elections on Saturday.

While three victims, who are all political workers, were allegedly killed by their suspected rivals in clashes at Birbhum, South Dinajpur and South 24-Parganas, the fourth lost his life in Murshidabad apparently while making bombs.

The death of four persons has raised the number of panchayat poll-related deaths to 20.

On Thursday, Alfaz Sheikh, a Congress worker from Daulatpur of Kulpi in South 24-Parganas, died at a private hospital in Calcutta.

Sheikh suffered multiple injuries when alleged Trinamul-backed goons beat him up with rods and sticks while he was campaigning for his party candidate at Daulatpur on July 3.

"Sheikh was going around the village asking for votes. Suddenly Trinamul supporters surrounded him from all sides and asked him to stop the campaign. A heated argument ensued between Sheikh and Trinamul supporters, who beat him up with rods and sticks," said a relative.

Initially treated at a local hospital, he was later shifted to Calcutta as his condition worsened, said a Congress leader in Kulpi.

Dilip Mahara, a BJP worker and the husband of an Independent candidate from Birbhum's Muhammadbazar, was found dead on Thursday.

Police recovered his body from the banks of a pond on Thursday morning. His wife, Chabi Mahara, and the local BJP leadership accused Trinamul of Mahara's murder.

Trinamul leadership, however, termed the death a fallout of BJP's internal feuding.

"There is enough indication of a feud in the party since the wife of the deceased BJP worker was a contestant," a Trinamul leader said.

In South Dinajpur's Dipkhanda-Daralhat Trinamul worker, Samir Burman, 34, was killed by unidentified goons.

Police and residents spotted him lying in a field near his home with burn injuries on Thursday morning. He was rushed to Balurghat district hospital where he was declared dead. Police and family sources said that the deceased left home to attend a picnic on Wednesday night and went missing.

Local Trinamul leadership accused the BJP of the murder.

"Samir was an active party worker. It is not clear why he was killed. But the way the BJP has unleashed terror and attacked our party workers, we don't rule out its hand," a local Trinamul leader said.

South Dinajpur SP Rahul De said: "Investigation has begun but it would be too early to comment about the motive behind the murder."

The fourth death occurred at Bhabta Maheshpur in Murshidabad's Beldanga where the police recovered the body of Kamal Sheikh, a Congress supporter, from a field on Thursday morning.

The police said the deceased, a close associate of local Congress leader and panchayat samiti candidate, Julekha Sheikh, was killed in a blast when he was allegedly making bombs. The police recovered items used in making bombs.

The Congress denied the charge and blamed Trinamul for the "murder".

Unidentified persons tried to kill Badar Sheikh, a CPM candidate in Raghunathganj-1, Murshidabad, on Wednesday night. CPM politburo member Ramchandra Dome accused "goons associated with the ruling party". Trinamul denied the charge.