A boy was killed days before his eighth birthday and 11 were wounded when a crude bomb went off at a crowded marketplace in Kolkata’s Dumdum on Tuesday. This was the first such explosion in the city since 1993, and triggered a war of words between the ruling Trinamool Congress (TMC) and Bharatiya Janata Party (BJP).The TMC blamed the BJP, which has been trying to make inroads into the state, and its parent organisation, Rashtriya Swayamsevak Sangh (RSS), for the blast.It said the explosion could have been an attempt on South Dumdum municipality chairman Pachu Roy’s life. The BJP and the RSS rubbished the charges and instead blamed the TMC.The boy was identified as Bibhas Ghosh. His mother was injured as well and was battling for her life at a hospital. West Bengal minister Jyotipriyo Mullick said two of the 11 injured were in critical condition.The explosion was strong enough to shatter glass panes of adjoining buildings and partially mangle a shutter near the blast scene. “Preliminary investigation has revealed the blast was caused by a bomb of low intensity,” said Barrackpore police commissioner Rajesh Kumar Singh.The BJP demanded that the probe into the blast be handed over to the federal anti-terror organisation, the National Investigation Agency (NIA), even as Mullick blamed it for the explosion. “They (the BJP) are targeting Dumdum since we (TMC) are immensely popular in this area. We are going to resist this plan politically,” said Mullick.Mullick’s ministerial colleague, Purnendu Bose, who rushed to the scene along with Rajya Sabha member Dola Sen, too, blamed the BJP and the RSS. RSS’s South Bengal unit general secretary, Jisnu Basu, regretted that people in responsible positions were making such allegations. “The RSS never indulges in acts of violence,” Basu said.State BJP chief Dilip Ghosh said blasts were taking place close to Trinamool offices. “The ruling party offices have become dens of anti-socials. Be it in Khagragarh, West Midnapore, Birbhum or Dumdum, all explosions are taking place inside or close to Trinamool offices. It is ridiculous that the ruling party leaders are blaming the BJP.”The Criminal Investigation Department’s bomb squad officers visited the blast scene and collected samples including a bag and splinters.The last such explosion in Kolkata had taken at Bowbazar bazaar in March 1993. As many as 69 people were killed when crude bombs went off accidentally at the house of a local gangster.In October 2014, a blast inside a building at Khagragarh had exposed banned Bangladeshi group Jamaat-ul Mujahideen’s network in Bengal. National Investigation Agency probe had later found the network was involved in plotting to overthrow Prime Minister Sheikh Hasina government in Bangladesh.