Kolkata, Aug 27 : At least seven people are killed and several others injured following a massive blast at an illegal firecracker factory at Duttapukur in West Bengal's North 24 Parganas district on Sunday. The death figures are likely to increase further, said local police sources, as the condition of some of those injured in the blast was extremely critical. Although the police are claiming that the death figure to be seven till the time the report was filed, local eyewitnesses said that they have witnessed at least 12 bodies being taken into ambulances and shifted from the spot of the accident. The blast, according to the local people, took place at around 9.30 a.m. on Sunday. The impact of the blast was such that even the roof of the warehouse where the fire-cracker raw materials were illegally stacked was blown off completely. The dead persons included a couple of women. Following the blasts, the local people started protesting and they alleged that the fire-cracker warehouse was running illegally for quite some time with the active backing from the local police. Repeated complaints of the local people for police action against the warehouse had fallen on deaf ear, the local people complained. Some of the locals even made an attempt to attack the house of the owner of the warehouse. After a huge police contingent reached the post, the locals started protesting seeking clarifications on why the police were silent for such a long time. There was a heated exchange of words between the police and the protesting public. The development is a blatant proof that two consecutive similar blasts at illegal firecracker factories first in East Midnapore and then in South 24 Parganas district were not eye-openers for the administration or the police. On May 16 this year, as many as nine persons died in a similar blast at an illegal firecracker factory at Egra in East Midnapore district. The owner of the factory Bhanu Bag was among those killed in the blast. Again on May 21, there was a similar blast at Budge Budge in South 24 Parganas district. Though no one was killed in the blast, some were injured and the event revealed how the entire Budge Budge area had become a hub for illegal firecracker factories and warehouses. /IANS