Another victim, injured in the cylinder blast in Rupnagar Residential Area of the city, died at Dhaka Medical College Hospital early Thursday, raising the death toll to seven.
The deceased was identified as Neha, 8.
Abul Kalam Azad, officer-in-charge of Rupnagar Police Station, said Neha succumbed to her injuries around 5am.
Meanwhile, Sub-Inspector Sumon filed a case against the balloon vendor Abu Syed, who is undergoing treatment at the hospital under police custody, in this connection around 3am.
Six children were killed and 21 people injured in the cylinder blast while gas was being pumped into balloons by a vendor in Rupnagar Residential Area of the city on Wednesday afternoon.
All of the deceased were residents of Quamrul Matbarer Bosti (slum).
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