"The emergency services have nothing more to do here - the work is finished," Tchouprian was quoted as saying by the Interfax news agency. Nearly 900 people involved in rescue and recovery efforts braved temperatures as low as minus 27 degrees Celsius (minus 16 degrees Fahrenheit) to search through mangled concrete and metal at the site.
Six people including two children were rescued at the site, but no survivors have been found since Tuesday when a 10-month-old boy was retrieved in what officials described as a "New Year's miracle". The explosion tore through the 10-storey building in the industrial city nearly 1,700 kilometres (1,050 miles) east of Moscow in the early hours of Monday. The Soviet-era block was home to about 1,100 people and the explosion destroyed 35 apartments, leaving dozens homeless.