Punjab Police and security agencies are conducting investigations into a blast in a car near Bathinda which left three people dead and 11 others injured, police officials said on Wednesday.

The blast took place on Tuesday evening just after Congress candidate Harminder Singh Jassi addressed a political gathering in Maur Mandi town about 200 km from Chandigarh.

Jassi, who is a relative of Dera Sacha Sauda sect chief Gurmeet Ram Rahim Singh, was whisked away by his security personnel following the blast.

The victims included a child, who was killed in the blast that took place just days before the February 4 assembly polls in the state. Campaigning in the state is at its peak.

Those seriously injured were rushed to hospitals in Maur Mandi and Bathinda.

Eyewitnesses said that the white Maruti 800 car, in which the explosion took place was completely destroyed. It was parked at the spot for some time and despite repeated police announcements it was not removed.

The eyewitnesses claimed that a pressure cooker was found lying near the car.

The police have not rule out conspiracy behind the incident.

Within hours of the blast, the political blame game started with Punjab Deputy Chief Minister and ruling Shiromani Akali Dal President Sukhbir Singh Badal blaming the incident on the Aam Aadmi Party's alleged nexus with radical elements.

"We have been asking the Election Commission to take note of the manner in which AAP convener Arvind Kejriwal is consorting with extremist forces. The bomb blast proves that our apprehensions were correct and that radical elements have infiltrated into Punjab in league with AAP," Badal said in a statement. 

While pointing out that the bomb blast was carried out in the same way as during days of terrorism in Punjab, Badal said: "It has been reported that there were twin ED devices and that the scooter and car used for the attack sported fake numbers and even the numbers of their chassis and engine were scrapped off."

Badal asked the Election Commission to keep a strict watch on radical elements who, he alleged, had become active in the state after a long time.

"It would be best to watch the activities of undesirable elements who have entered the state in the name of canvassing for AAP. These people are being funded to foment trouble in Punjab. If they are not nipped in the bud there could be more such incidents," Badal added.

Punjab Congress President Amarinder Singh termed the blast as a "conspiracy against the Congress, which was set for a landslide victory in the assembly polls".

"The incident has proved my worst fears that armed criminals and goondas had been let loose by the rival political parties in a desperate bid to scuttle the Congress ride to a sweeping win in the elections," Singh said.

Demanding further strengthening of security in poll-bound Punjab, Singh said: "The situation is highly volatile. With the entry of AAP-sponsored outsiders tensions have escalated."

"It was futher triggered by reports of criminal gangs being given a free hand by the Badal government to create mayhem during the polls."

"The Naxal-Khalistani nexus promoted by Arvind Kejriwal's Aam Aadmi Party has transformed the state into a tinder-box waiting to explode," Singh said, expressing apprehensions of further violence over the next four days, up to the polling on Saturday.

He said that he had already communicated his fears to the Election Commission, pointing out that more than 50,000 outsiders brought to Punjab by AAP from other states like Bihar and Uttar Pradesh has further charged the tense atmosphere in the state.

Singh and Badal have already condemned Kejriwal's controversial stay at the house of a Khalistan Commando Force (KCF) extremist in Punjab recently.