Kochi, Oct 30 : With a 13 -year-old girl succumbing to her injuries, the death toll in the two explosions that rocked the Christian convention centre in Kerala's Kalamassery has mounted to three, sources said on Monday. The girl had suffered over 90 per cent burns in the blasts that took place in a hall where prayers were underway on Sunday. She breathed her last, past midnight. On Monday morning, teams of the NSG, including forensic experts, and NIA reached the spot. Now all eyes are on the NIA, if they will take up the probe, as Kerala Police called it a "closed" case after one Dominic Martin from Kochi surrendered before the police claiming responsibility. Martin told the police that he committed the crime "because Jehovah Witness was on the wrong track". The Kerala Police claimed to have cracked the case after the relatives of the woman who died instantly after the explosion identified the body. Till her relatives approached, the Police had suspected the deceased woman to be a "suspect". Fifty-three-year-old Kumari from Thodupuzha- Kumari was the second woman to have succumbed. Notably, Jehovah Witnesses are a group of Christians who do not identify themselves as Protestants. The Jehovah Witness Convention is an annual gathering where large assemblies called Regional Conventions take place for three days. The event had started last Friday and it was to end on Sunday. Martin's arrest will be recorded later in the day. Now, it remains to be seen whether the NIA will take up the case as according to the rules, the state government has to ask for it, if not, the Centre can take it up directly. Investigations into the double-bomb blasts revealed that an Improvised Explosive Device (IED) hidden in a tiffin box was used to trigger the explosion. Later, Martin told the police that he had come live on Facebook before the incident, which was verified from his mobile phone. The police have identified the lodge in Chalakudy where Martin stayed. As per the lodge authorities, the accused returned around 10.30 a.m on Sunday and vacated the room in ten minutes stating that he met with an accident. He had produced his identity card before taking up the room. Martin lives in Kochi in a rented accommodation after returning from Dubai, where he worked for the past six years, a month ago. He was a member of the Jehovah's Witnesses. /IANS