<p>A forensic team started an investigation at the site of an LPG cylinder blast in Kolkata's Garden Reach area in which 21 people, including two minors, were injured, police said on Friday.</p>.<p>The blast occurred on the ground floor of a house on Bichalighat Road on Thursday evening when the occupants were preparing food.</p>.<p>All the 21 people suffered burn injuries, and of them, three are critical while the condition of the remaining people is stable and they are also undergoing treatment at the hospital.</p>.<p>The forensic team will collect samples from the spot and those will be chemically tested to ascertain the exact cause of the explosion, a police officer told <em>PTI</em>.</p>.<p>"Even though gas leakage seems to be the reason behind the explosion, we need to find out if there is any other reason behind the blast," the officer said.</p>
<p>A forensic team started an investigation at the site of an LPG cylinder blast in Kolkata's Garden Reach area in which 21 people, including two minors, were injured, police said on Friday.</p>.<p>The blast occurred on the ground floor of a house on Bichalighat Road on Thursday evening when the occupants were preparing food.</p>.<p>All the 21 people suffered burn injuries, and of them, three are critical while the condition of the remaining people is stable and they are also undergoing treatment at the hospital.</p>.<p>The forensic team will collect samples from the spot and those will be chemically tested to ascertain the exact cause of the explosion, a police officer told <em>PTI</em>.</p>.<p>"Even though gas leakage seems to be the reason behind the explosion, we need to find out if there is any other reason behind the blast," the officer said.</p>