Unidentified miscreants hurled bombs and opened fire outside the residence of Bharatiya Janata Party leader and former MP Arjun Singh in West Bengal's Bhatpara, police said on Thursday.
A youth suffered injuries in the attack that took place late on Wednesday, they said.
Singh and his close associates reportedly chased the assailants, forcing them to flee the spot.
"The situation is now under control. Those involved will not be spared... legal action will be taken against the culprits," Barrackpore Police Commissioner Ajay Thakur said.
Singh alleged that Trinamool Congress (TMC) councillor Sunita Singh's son, Namit Singh, was behind the attack.
"He opened fire in front of the police. There was indiscriminate firing and bombing," the former MP claimed.
According to police sources, the violence erupted following a dispute between two groups of workers at Meghna Jute Mill in the area.
Meanwhile, TMC's Jagaddal MLA Somnath Shyam accused Singh and his supporters of instigating violence.
"Arjun Singh and his men attacked workers in the Meghna Jute Mill and fired bullets. The youth was shot by Singh, and three to four more people were injured in his group's attack. We demand Singh's immediate arrest, or we will launch a larger protest," he said.
Namit Singh reportedly arrived at the scene after receiving reports of the unrest.
Soon after, the situation escalated, leading to gunfire and bombing, police said.
Describing the sequence of events, Singh said, "Around 10:30 pm, I suddenly heard two rounds of gunshots. I was in Majdoor Bhavan with my close associates. I rushed outside and headed towards Meghna Mor. As soon as we reached the spot, miscreants opened fire at us."
Singh claimed that at least five to seven rounds were fired.
Following the attack, he and his associates chased the assailants, during which one of them fell into a drain and suffered injuries.
A large police contingent, including Rapid Action Force (RAF) personnel, was deployed in the area to control the situation.
Several empty cartridges and live bombs have been recovered from the spot, officials said.
The injured youth was initially taken to Bhatpara State General Hospital. As his condition deteriorated, he was shifted to a hospital in Kolkata, police said.
Patrolling has been intensified in Bhatpara to prevent any further escalation, the officials added.