A powerful blast on Wednesday rocked Allahabad's Kareli locality claiming the lives of at least six persons, including four children and two women. At least 12 people have also been injured in the explosion and six of them are said to be in critical condition. Those injured in the blast have been rushed to nearby hospital for treatment. Top officials of the local administration and police teams have reached the spot to take stock of the situation. The entire area has been cordoned off and the authorities have begun investigation into the matter. Meanwhile a forensic team from Lucknow has also been rushed to Allahabad.