Two women were killed and 51 people were injured, six critically, when at least two low-intensity blasts went off at a prayer meeting of the Christian denomination Jehova’s Witnesses at Kalamassery in Kerala on Sunday.

Hours later, a man named Dominic Martin surrendered to police claiming he had carried out the blasts because the Jehova’s Witnesses were allegedly involved in “anti-national” activities.

Chief minister Pinarayi Vijayan told a news conference in Thiruvananthapuram that stringent action would be taken against anyone carrying out hate campaigns in connection with the blasts.

The explosive devices went off in quick succession around 9.40am, minutes after more than 2,000 devotees had begun their prayers on the last day of a three-day regional convention of the Jehovah’s Witnesses at the Zamra International Convention Centre in Kalamassery.

Before his surrender, Martin purportedly went live on Facebook to claim responsibility for the bombing.

“My name is Martin…. There has been a bomb blast and serious consequences at a convention organised by Jehovah’s Witnesses…. I am taking full responsibility for it. I am behind that bomb blast,” a bespectacled man in a blue shirt is seen claiming in a video telecast by Malayalam channels.

The man purportedly says he had been a member of the denomination for 16 years before severing ties with it.

“I am doing this video to make you understand why I planted the bomb…. About six years ago I realised this is the wrong kind of organisation that is involved in anti-national activities. I repeatedly urged them to rectify that. But none of them was ready to do that,” the man appears to say in Malayalam.

Martin’s Facebook page appears to have been blocked after the video attracted public attention.

In the video, the man in the blue shirt alleges that Jehovah’s Witnesses have been “injecting poison” into elders and children alike, teaching them to hate the nation and its people.

“I can only react to this wrong ideology. I had to take such a decision since this ideology is a threat to the nation,” the man purportedly says.

“Political parties will not intervene since everyone is scared of religion. You need to open your eyes, because ordinary people like me are forced to give our lives since you don’t control people who spread the wrong ideology.”

He signs off, saying he is going to surrender to the police.

Martin surrendered at Kodakara police station in Thrissur district, some 45km from Kalamassery, an industrial township in Ernakulam district.

As the police questioned him, a team of investigators searched his home in Thammanam, about 12km from Kalamassery, in Ernakulam.

Additional director-general of police M.R. Ajith Kumar confirmed Martin’s surrender but declined to reveal details saying he was being questioned.

Sreekumar, PRO with Jehovah’s Witnesses in Ernakulam district, told reporters he had known such a person about five years ago but he wasn’t actively involved with the denomination any more.

Personnel from the emergency services and the police arrived at the spot within minutes of the blasts and rushed the injured to the Government Medical College, just over 1km away.

State health minister Veena George, who supervised the treatment of the injured at the government medical college and three private hospitals, said that six of the 51 injured, who suffered burns, were critical. One of them, a 12-year-old child, was on ventilator.

One of the dead women, who succumbed to her injuries in the evening, was aged 53. The other is charred and yet to be identified.

Video clips shot on mobile phones by those inside the hall showed chairs in flames in two spots a few metres from each other.

Vijayan said a 20-member investigation team had been formed. “We have also called an all-party meeting tomorrow (Monday), when things will be clearer,” he said.

In an FIR registered before Martin came into the picture, the police invoked provisions of the Explosive Substances Act and the anti-terror Unlawful Activities (Prevention) Act.

Martin’s wife told the police he had left home at dawn on Sunday, but said she didn’t know about his alleged plan to set off blasts.

The police claim to have recovered a set of tools and wires from Martin’s home, which they think may have been used to assemble the explosive devices. Martin is believed to have made the bombs using information available freely on the Internet.

However, the investigators are also verifying every bit of his “confession” to make sure he had acted alone.